Search Resources

49 Results

View
Selected filters:
  • Triangle
30-60-90 triangle
Conditions of Use:
Read the Fine Print
Rating

An interactive applet and associated web page that demonstrate the properties of a 30-60-90 triangle. The applet shows a right triangle that can be resized by dragging any vertex. As it is dragged, the remaining vertices change so that the triangle's angles remain 30 degrees, 60 degrees and 90 degrees The text on the page points out that the sides of a 30-60-90 triangle are always in the ratio of 1 : 2 : root 3 Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

Subject:
Geometry
Material Type:
Reading
Simulation
Provider:
Math Open Reference
Author:
John Page
Date Added:
02/16/2011
3:4:5 triangle
Conditions of Use:
Read the Fine Print
Rating

An interactive applet and associated web page that demonstrate the properties of a 3:4:5 triangle - one of the Pythagorean triples. The applet shows a right triangle that can be resized by dragging any vertex. As it is dragged, the remaining vertices change so that the triangle's side remain in the ration 3:4:5. The text on the page has an example of how the triangle can be used to measure a right angle on even large objects. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

Subject:
Geometry
Material Type:
Reading
Simulation
Provider:
Math Open Reference
Author:
John Page
Date Added:
02/16/2011
45-45-90 triangle
Conditions of Use:
Read the Fine Print
Rating

An interactive applet and associated web page that demonstrate the properties of a 45-45-90 isosceles right triangle. The applet shows a right triangle that can be resized by dragging any vertex. As it is dragged, the remaining vertices change so that the triangle's angles remain 45 degrees, 45 degrees and 90 degrees The text on the page points out that the sides of a 45-45-90 triangle are always in the ratio of 1 : 2 : root 2 Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

Subject:
Geometry
Material Type:
Reading
Simulation
Provider:
Math Open Reference
Author:
John Page
Date Added:
02/16/2011
AAA Doesn't work
Conditions of Use:
Read the Fine Print
Rating

An interactive applet and associated web page that shows that angle-angle-angle (AAA) is not enough to prove congruence. The applet shows two triangles, one of which can be dragged to resize it, showing that although they have the same angles they are not the same size and thus not congruent. The web page describes all this and has links to other related pages. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

Subject:
Geometry
Material Type:
Reading
Simulation
Provider:
Math Open Reference
Author:
John Page
Date Added:
02/16/2011
AAA Triangle similarity test
Conditions of Use:
Read the Fine Print
Rating

An interactive applet and associated web page showing how the AAA similarity test works. Two similar triangles are shown that can be resized by dragging. The other triangle adjusts to remain similar and the angle-angle-angle elements are highlighted to show how they are involved in this test of similarity. (all three interior angles congruent). The web page describes all this and has links to other related pages. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference interactive geometry reference book project at http://www.mathopenref.com.

Subject:
Geometry
Material Type:
Reading
Simulation
Provider:
Math Open Reference
Author:
John Page
Date Added:
02/16/2011
AAS Congruent Triangles
Conditions of Use:
Read the Fine Print
Rating

An interactive applet and associated web page that shows how triangles that have two angles and a non-included side the same must be congruent. The applet shows two triangles, one of which can be reshaped by dragging any vertex. The other changes to remain congruent to it and the two angles and non-included side are outlined in bold to show they are the same measure and are the elements being used to prove congruence. The web page describes all this and has links to other related pages. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

Subject:
Geometry
Material Type:
Reading
Simulation
Provider:
Math Open Reference
Author:
John Page
Date Added:
02/16/2011
ASA Congruent Triangles
Conditions of Use:
Read the Fine Print
Rating

An interactive applet and associated web page that shows how triangles that have two angles and their included side the same must be congruent. The applet shows two triangles, one of which can be reshaped by dragging any vertex. The other changes to remain congruent to it and the two angles and the included side are outlined in bold to show they are the same measure and are the elements being used to prove congruence. The web page describes all this and has links to other related pages. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

Subject:
Geometry
Material Type:
Reading
Simulation
Provider:
Math Open Reference
Author:
John Page
Date Added:
02/16/2011
Acute triangle
Conditions of Use:
Read the Fine Print
Rating

An interactive applet and associated web page that demonstrate the three types of triangle: acute, obtuse and right. The applet shows a triangle that is initially acute (all angles less then 90 degrees) which the user can reshape by dragging any vertex. There is a message changes in real time while the triangle is being dragged that tells if the triangle is an acute, right or obtuse triangle and gives the reason why. By experimenting with the triangle student can develop an intuitive sense of the difference between these three classes of triangle. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

Subject:
Geometry
Material Type:
Reading
Simulation
Provider:
Math Open Reference
Author:
John Page
Date Added:
02/16/2011
Area of a triangle (Coordinate Geometry)
Conditions of Use:
Read the Fine Print
Rating

An interactive applet and associated web page that calculate the area of a triangle using the formula method in coordinate geometry. The applet has a triangle with draggable vertices. As you drag them the triangle's area is recalculated from the vertex coordinates using the formula. The grid and coordinates can be turned on and off. The area calculation can be turned off to permit class exercises and then turned back on the verify the answers. The applet can be printed as it appears on the screen to make handouts. The web page has a full description of the method for determining area using the formula method, a worked example and has links to other pages relating to coordinate geometry. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

Subject:
Geometry
Material Type:
Reading
Simulation
Provider:
Math Open Reference
Author:
John Page
Date Added:
02/16/2011
Area of a triangle (conventional method)
Conditions of Use:
Read the Fine Print
Rating

An interactive applet and associated web page that explain the area of a triangle. The applet shows a triangle that can be reshaped by dragging any vertex. As it changes, the area is continually recalculated using the 'half base times height' method. The triangle has a fixed square grid in its interior that can be used to visually estimate the area for later correlation with the calculated value. The calculation can be hidden while estimation is in progress. The text page has links to a similar page that uses Heron's Formula to compute the area. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

Subject:
Geometry
Material Type:
Reading
Simulation
Provider:
Math Open Reference
Author:
John Page
Date Added:
02/16/2011
Area of a triangle using the box method (Coordinate Geometry)
Conditions of Use:
Read the Fine Print
Rating

An interactive applet and associated web page that calculate the area of a triangle using the box method in coordinate geometry. The applet has a triangle with draggable vertices. As you drag them the triangle's bounding box is shown and the area recalculated by subtracting the areas of the outside triangles. The grid and coordinates can be turned on and off. The area calculation can be turned off to permit class exercises and then turned back on the verify the answers. The applet can be printed as it appears on the screen to make handouts. The web page has a full description of the method for determining area using the box method, a worked example and has links to other pages relating to coordinate geometry. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

Subject:
Geometry
Material Type:
Reading
Simulation
Provider:
Math Open Reference
Author:
John Page
Date Added:
02/16/2011
Congruent Triangles
Conditions of Use:
Read the Fine Print
Rating

An interactive applet and associated web page that demonstrate the concept of congruent triangles. Applets show that triangles a re congruent if the are the same, rotated, or reflected. In each case the user can drag one triangle and see how another triangle changes to remain congruent to it. The web page describes all this and has links to other related pages. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

Subject:
Geometry
Material Type:
Reading
Simulation
Provider:
Math Open Reference
Author:
John Page
Date Added:
02/16/2011
Constructing an equilateral triangle
Conditions of Use:
Read the Fine Print
Rating

An interactive applet and associated web page that provide step-by-step instructions on how to construct an equilateral triangle with a given side length using only a compass and straightedge. The animation can be run either continuously like a video, or single stepped to allow classroom discussion and thought between steps. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

Subject:
Geometry
Material Type:
Reading
Simulation
Provider:
Math Open Reference
Author:
John Page
Date Added:
02/16/2011
Constructing the Incenter of a triangle
Conditions of Use:
Read the Fine Print
Rating

An interactive applet and associated web page that provide step-by-step animated instructions on how to construct the incenter of a triangle. The animation can be run either continuously like a video, or single stepped to allow classroom discussion and thought between steps. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

Subject:
Geometry
Material Type:
Reading
Simulation
Provider:
Math Open Reference
Author:
John Page
Date Added:
02/16/2011
Design and Fly a Kite
Conditions of Use:
Read the Fine Print
Rating

Students learn how to use wind energy to combat gravity and create lift by creating their own tetrahedral kites capable of flying. They explore different tetrahedron kite designs, learning that the geometry of the tetrahedron shape lends itself well to kites and wings because of its advantageous strength-to-weight ratio. Then they design their own kites using drinking straws, string, lightweight paper/plastic and glue/tape. Student teams experience the full engineering design cycle as if they are aeronautical engineers—they determine the project constraints, research the problem, brainstorm ideas, select a promising design and build a prototype; then they test and redesign to achieve a successful flying kite. Pre/post quizzes and a worksheet are provided.

Subject:
Mathematics
Geometry
Material Type:
Activity/Lab
Provider:
TeachEngineering
Provider Set:
TeachEngineering
Author:
Joshua T. Claypool
Date Added:
02/17/2017
Engineering Your Own Spectrograph
Conditions of Use:
Read the Fine Print
Rating

Students use simple materials to design an open spectrograph so they can calculate the angle light is bent when it passes through a holographic diffraction grating. A holographic diffraction grating acts like a prism, showing the visual components of light. After finding the desired angles, students use what they have learned to design their own spectrograph enclosure.

Subject:
Engineering
Physics
Material Type:
Activity/Lab
Provider:
TeachEngineering
Provider Set:
TeachEngineering
Date Added:
10/14/2015
Equilateral triangle
Conditions of Use:
Read the Fine Print
Rating

An interactive applet and associated web page that demonstrate equilateral triangles (all sides the same length). The applet presents an equilateral triangle where the user can drag any vertex. As the vertex is dragged, the others move automatically to keep the triangle equilateral. The angles are also updated continuously to show that the all interior angles are always congruent. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

Subject:
Geometry
Material Type:
Reading
Simulation
Provider:
Math Open Reference
Author:
John Page
Date Added:
02/16/2011
Fence That Farmland!
Conditions of Use:
Read the Fine Print
Rating

Students develop and solidify their understanding of the concept of "perimeter" as they engage in a portion of the civil engineering task of land surveying. Specifically, they measure and calculate the perimeter of a fenced in area of "farmland," and see that this length is equivalent to the minimum required length of a fence to enclose it. Doing this for variously shaped areas confirms that the perimeter is the minimal length of fence required to enclose those shapes. Then students use the technology of a LEGO MINDSTORMS(TM) NXT robot to automate this task. After measuring the perimeter (and thus required fence length) of the "farmland," students see the NXT robot travel around this length, just as a surveyor might travel around an area during the course of surveying land or measuring for fence materials. While practicing their problem solving and measurement skills, students learn and reinforce their scientific and geometric vocabulary.

Subject:
Engineering
Material Type:
Activity/Lab
Provider:
TeachEngineering
Provider Set:
TeachEngineering
Author:
Ursula Koniges
Date Added:
09/18/2014
Five Pointed Star Origami
Conditions of Use:
Remix and Share
Rating

Origami is the Japanese art of paper folding, originally from China and now practiced all over the world. In this activity, create an origami star. Introduce children to both geometry and analytical skills in a creative way.

Subject:
Arts and Humanities
Astronomy
Material Type:
Activity/Lab
Game
Provider:
UNAWE
Provider Set:
EU Universe Awareness
Date Added:
03/20/2012
Handy Measuring Ratio
Conditions of Use:
Remix and Share
Rating

In this activity, learners use their hands as tools for indirect measurement. Learners explore how to use ratios to calculate the approximate height of something that can't be measured directly by first measuring something that can be directly measured. This activity can also be used to explain how scientists use indirect measurement to determine distances between things in the universe that are too far away, too large or too small to measure directly (i.e. diameter of the moon or number of bacteria in a volume of liquid).

Subject:
Mathematics
Material Type:
Activity/Lab
Provider:
Exploratorium
Author:
Exploratorium
Gordon and Betty Moore Foundation
National Science Foundation
The Exploratorium
Date Added:
12/07/2010
How would you build your dream playground with basic shapes?
Rating

Overall Goal: During this lesson we will cover basic shapes and learn how they can be used in everyday objects. Our goal is for students to know the basic shapes, find them in objects such as playgrounds, be able to create their own playground using shapes, and finally be able to tell the class about the playground they made and the shapes used.  Standard: K.G.3: Model shapes in the world by composing shapes from objects (e.g., sticks and clay balls) and drawing shapes. Learning Objectives: The students will be able to show they know what each of the basics shape are by correctly drawing a square, triangle, rectangle, circle, and oval.Students will be able to create playground with the basic shapes by using everyday objects such as play-doh, craft sticks, etc.Students will be able to complete the project by creating their dream playground; using all of the shapes covered in the lesson.Students can explain their playgrounds and shapes they used, and why their specific playground represents their “dream playground” by presenting their project to the class. Key Terms:SquareRectangleTriangleOvalCircle Lesson Introduction:We will visit the school playground to have the students find the different shapes in the playground equipment. We want students to use the playground visit to help them decide how they would build their dream playground using the basic shapes. We will give the students a packet (found in the Resources section) that includes a few activities for them to do before the main lesson. They will take this to the playground and fill out the second page by writing down the different playground structures that fit each shape. They will be able to explore the playground on their own, so that they can have different answers than each other. Main Lesson:In class, we will have the students create, by drawing, their ‘dream playground’ using the specific basic shapes they are given to work with (squares, triangles, circles, rectangles, and ovals). They will be given 20 minutes to complete their drawing. They will be able to draw this on paper or use a computer application to create this.After this, the students will be given play-doh and popsicle sticks to recreate the shapes and structures that they had on their paper. The crafting process should take around 50 minutes. The drawings and crafts will be assessed by if the students correctly demonstrate their knowledge of the different shapes and how to create them.At the end, the kids will present their own playgrounds to the class and show what shapes they used and be able to explain and defend why it is their dream playground. This is so that the teacher can tell if the student knows the shapes and is able to defend their argument of what makes it a dream playground. The students will be able to use pencil and paper to draw or use tablets/iPads and use a drawing application. Lesson Ending:When the students are done creating their projects, they will each present their playgrounds to the class and explain the individual shapes that they used. The students will also explain why they believe their playground model is the best. The students should answer the following questions when they defend why their playground is the best. How many of each shape are in your playground? Is one of the five shapes better for making playgrounds than the others and why? The way that we can assess is if the student created the shapes correctly and correctly referenced them in their presentation. Rubric:The students will be graded as Good, Average, or Poor. The following is what they are going to be graded on:Students know basic shapesStudents use shapes correctly to build a playgroundStudents complete all parts of the projectStudents present their playgrounds to the class and can explain how they built their playground with the basic shapes Differentiation:This project should not affect students of different gender, race, culture, or sexual identity. Students with behavioral challenges will be worked more one-on-one than the other students to make sure that any confusion or frustration will be handled. The higher ability learners can go beyond the four shapes specified, if they feel comfortable. The project does not require out of school time where they would absolutely need a computer or Wifi access.Examples:If high ability students feel like they can add shapes that are not on the required list, they may do so with permission from the teacher. They will not be given any extra credit for adding other shapes, but this is a good way for the teachers to see where some students are at academically.If there is a child with dyslexia they will receive extra help from the teacher to be sure that they can accurately read the instructions on the papers.If a student needs to use a computer drawing application for sketching the playground because of a disability but doesn’t understand how to use it, they may come into class early to spend some extra time navigating the site.Since the students will be doing a worksheet after the activity, there might be students who struggle with reading. If the students struggle with reading the worksheet, they may ask, and we will help them through the parts that they find confusing. If the student has translation issues with some of the words, we will also help them translate it. This will be done just through being familiar with the material and specific language. Anticipated Difficulties:There could be difficulty with children being distracted at the playground and while crafting. We will need to be sure that everyone is staying on task by keeping them engaged during all of the activities. Children can sometimes become distracted if they are just listening to someone speak and by keeping them engaged and involving them during all of the lesson they will be more likely to stay focused. When on the playground we can use students to help point out the shapes that we find and also ask questions during this time to keep students attentive. Students might be at different learning levels and could struggle with learning the shapes. If so, we could always split the children into a few groups based on learning levels to help the lesson run smoother.

Subject:
Geometry
Material Type:
Lesson Plan
Author:
summer dickerhoof
Date Added:
12/07/2017
Isosceles triangle
Conditions of Use:
Read the Fine Print
Rating

An interactive applet and associated web page that demonstrate isosceles triangles (two sides the same length). The applet presents a triangle where the user can drag any vertex. As the vertex is dragged the others move automatically to keep the triangle isosceles. The angles are also updated continuously to show that the base angles are always congruent. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

Subject:
Geometry
Material Type:
Reading
Simulation
Provider:
Math Open Reference
Author:
John Page
Date Added:
02/16/2011
Launch into Learning: Catapults!
Conditions of Use:
Read the Fine Print
Rating

Students learn about catapults, including the science and math concepts behind them, as they prepare for the associated activity in which they design, build and test their own catapults. They learn about force, accuracy, precision and angles.

Subject:
Engineering
Physics
Material Type:
Lesson Plan
Provider:
TeachEngineering
Provider Set:
TeachEngineering
Author:
Carleigh Samson
Jake Crosby
Jonathan McNeil
Malinda Schaefer Zarske
William Surles
Date Added:
09/18/2014
Let’s Build an Aqueduct!
Conditions of Use:
Read the Fine Print
Rating

Students explore in detail how the Romans built aqueducts using arches—and the geometry involved in doing so. Building on what they learned in the associated lesson about how innovative Roman arches enabled the creation of magnificent structures such as aqueducts, students use trigonometry to complete worksheet problem calculations to determine semicircular arch construction details using trapezoidal-shaped and cube-shaped blocks. Then student groups use hot glue and half-inch wooden cube blocks to build model aqueducts, doing all the calculations to design and build the arches necessary to support a water-carrying channel over a three-foot span. They calculate the slope of the small-sized aqueduct based on what was typical for Roman aqueducts at the time, aiming to construct the ideal slope over a specified distance in order to achieve a water flow that is not spilling over or stagnant. They test their model aqueducts with water and then reflect on their performance.

Subject:
Mathematics
Geometry
Material Type:
Activity/Lab
Provider:
TeachEngineering
Author:
Lauchlin Blue
Malinda Zarske
Nathan Coyle
Date Added:
02/07/2017
Obtuse triangle
Conditions of Use:
Read the Fine Print
Rating

An interactive applet and associated web page that demonstrate the three types of triangle: acute, obtuse and right. The applet shows a triangle that is initially obtuse (one angle greater than 90 degrees) which the user can reshape by dragging any vertex. There is a message changes in real time while the triangle is being dragged that tells if the triangle is an acute, right or obtuse triangle and gives the reason why. By experimenting with the triangle student can develop an intuitive sense of the difference between these three classes of triangle. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

Subject:
Geometry
Material Type:
Reading
Simulation
Provider:
Math Open Reference
Author:
John Page
Date Added:
02/16/2011
Olympic Engineering
Conditions of Use:
Read the Fine Print
Rating

The lesson begins by introducing Olympics as the unit theme. The purpose of this lesson is to introduce students to the techniques of engineering problem solving. Specific techniques covered in the lesson include brainstorming and the engineering design process. The importance of thinking out of the box is also stressed to show that while some tasks seem impossible, they can be done. This introduction includes a discussion of the engineering required to build grand, often complex, Olympic event centers.

Subject:
Architecture and Design
Engineering
Education
Mathematics
Geometry
Material Type:
Activity/Lab
Lesson Plan
Provider:
TeachEngineering
Provider Set:
TeachEngineering
Author:
Abigail Watrous
Denali Lander
Janet Yowell
Katherine Beggs
Melissa Straten
Tod Sullivan
Date Added:
09/18/2014
Pocket Protractor
Conditions of Use:
Remix and Share
Rating

In this activity, learners create angle-measuring devices--protractors--out of paper. Learners follow a series of steps to fold a square sheet of paper into a triangular Pocket Protractor. Learners will practice measuring and identifying the angles of a triangle.

Subject:
Geometry
Material Type:
Activity/Lab
Provider:
Exploratorium
Author:
Exploratorium
Gordon and Betty Moore Foundation
National Science Foundation
The Exploratorium
Date Added:
11/07/2010
Polygons, Angles and Trusses, Oh My!
Conditions of Use:
Read the Fine Print
Rating

Students take a close look at truss structures, the geometric shapes that compose them, and the many variations seen in bridge designs in use every day. Through a guided worksheet, students draw assorted 2D and 3D polygon shapes and think through their forms and interior angles (mental “testing”) before and after load conditions are applied. They see how engineers add structural members to polygon shapes to support them under compression and tension, and how triangles provide the strongest elemental shape. A PowerPoint® presentation is provided. This lesson prepares students for two associated activities that continue the series on polygons and trusses.

Subject:
Mathematics
Geometry
Material Type:
Lesson
Provider:
TeachEngineering
Author:
Andi Vicksman
Maia Vadeen
Malinda Zarske
Nathan Coyle
Russell Anderson
Ryan Sullivan
Sabina Schill
Date Added:
02/07/2017
Polygons and Popsicle Trusses
Conditions of Use:
Read the Fine Print
Rating

Students learn about the role engineers play in designing and building truss structures. Simulating a real-world civil engineering challenge, student teams are tasked to create strong and unique truss structures for a local bridge. They design to address project constraints, including the requirement to incorporate three different polygon shapes, and follow the steps of the engineering design process. They use hot glue and Popsicle sticks to create their small-size bridge prototypes. After compressive load tests, they evaluate their results and redesign for improvement. They collect, graph and analyze before/after measurements of interior angles to investigate shape deformation. A PowerPoint® presentation, design worksheet and data collection sheet are provided. This activity is the final step in a series on polygons and trusses.

Subject:
Mathematics
Geometry
Material Type:
Activity/Lab
Provider:
TeachEngineering
Author:
Andi Vicksman
Maia Vadeen
Malinda Zarske
Nathan Coyle
Russell Anderson
Ryan Sullivan
Sabina Schill
Date Added:
02/07/2017
Relationship of area and perimeter of a triangle
Conditions of Use:
Read the Fine Print
Rating

An interactive applet and associated web page that show the relationship between the perimeter and area of a triangle. It shows that a triangle with a constant perimeter does NOT have a constant area. The applet has a triangle with one vertex draggable and a constant perimeter. As you drag the vertex, it is clear that the area varies, even though the perimeter is constant. Optionally, you can see the path traced by the dragged vertex and see that it forms an ellipse. A link takes you to a page where this effect is exploited to construct an ellipse with string and pins. The applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

Subject:
Geometry
Material Type:
Reading
Simulation
Provider:
Math Open Reference
Author:
John Page
Date Added:
02/16/2011
Right on Target: Catapult Game
Conditions of Use:
Read the Fine Print
Rating

Students experience the engineering design process as they design and build accurate and precise catapults using common materials. They use their catapults to participate in a game in which they launch Ping-Pong balls to attempt to hit various targets.

Subject:
Engineering
Physics
Material Type:
Activity/Lab
Provider:
TeachEngineering
Provider Set:
TeachEngineering
Author:
Carleigh Samson
Jake Crosby
Jonathan McNeil
Malinda Schaefer Zarske
William Surles
Date Added:
09/18/2014
Right triangle
Conditions of Use:
Read the Fine Print
Rating

An interactive applet and associated web page that demonstrate the three types of triangle: acute, obtuse and right. The applet shows a triangle that is initially right (one angle 90 degrees) which the user can reshape by dragging any vertex. There is a message changes in real time while the triangle is being dragged that tells if the triangle is an acute, right or obtuse triangle and gives the reason why. By experimenting with the triangle student can develop an intuitive sense of the difference between these three classes of triangle. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

Subject:
Geometry
Material Type:
Reading
Simulation
Provider:
Math Open Reference
Author:
John Page
Date Added:
02/16/2011
Similar Triangles
Conditions of Use:
Read the Fine Print
Rating

An interactive applet and associated web page that demonstrate the concept of similar triangles. Applets show that triangles are similar if the are the same shape and possibly rotated, or reflected. In each case the user can drag one triangle and see how another triangle changes to remain similar to it. The web page describes all this and has links to other related pages. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

Subject:
Geometry
Material Type:
Reading
Simulation
Provider:
Math Open Reference
Author:
John Page
Date Added:
02/16/2011
Stay in Shape
Conditions of Use:
Read the Fine Print
Rating

Students learn that math is important in navigation and engineering. They learn about triangles and how they can help determine distances. Ancient land and sea navigators started with the most basic of navigation equations (speed x time = distance). Today, navigational satellites use equations that take into account the relative effects of space and time. However, even these high-tech wonders cannot be built without pure and simple math concepts — basic geometry and trigonometry — that have been used for thousands of years.

Subject:
Education
Material Type:
Activity/Lab
Provider:
TeachEngineering
Provider Set:
TeachEngineering
Author:
Janet Yowell
Jeff White
Malinda Schaefer Zarske
Matt Lippis
Penny Axelrad
Date Added:
10/14/2015
Straw Bridges
Conditions of Use:
Read the Fine Print
Rating

Working as engineering teams, students design and create model beam bridges using plastic drinking straws and tape as their construction materials. Their goal is to build the strongest bridge with a truss pattern of their own design, while meeting the design criteria and constraints. They experiment with different geometric shapes and determine how shapes affect the strength of materials. Let the competition begin!

Subject:
Architecture and Design
Engineering
Material Type:
Activity/Lab
Provider:
TeachEngineering
Provider Set:
TeachEngineering
Author:
Chris Valenti
Denali Lander
Denise W. Carlson
Joe Friedrichsen
Jonathan S. Goode
Malinda Schaefer Zarske
Natalie Mach
Date Added:
10/14/2015
Triangle
Conditions of Use:
Read the Fine Print
Rating

An interactive applet and associated web page that introduce the concept of a triangle. The applet shows a triangle where the user can drag the vertices to reshape it. As it is being dragged a base and altitude are shown continuously changing. Demonstrates that the altitude may require the base to be extended. The text on the page lists the properties of a triangle and lists the various triangle types, with links to a definition of each. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

Subject:
Geometry
Material Type:
Reading
Simulation
Provider:
Math Open Reference
Author:
John Page
Date Added:
02/16/2011
Triangle Circumcenter
Conditions of Use:
Read the Fine Print
Rating

The applet shows a triangle which the user can resize by dragging any of its vertices. It shows the three perpendicular bisectors of the sides and the point where they intersect - the circumcenter. These track the changes in the triangle in real time. It shows that the circumcenter may lie outside the triangle. The associated web page describes the properties of the circumcenter and points out that it the center of the triangle's circumcircle. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

Subject:
Geometry
Material Type:
Reading
Simulation
Provider:
Math Open Reference
Author:
John Page
Date Added:
02/16/2011
Triangle exterior angles
Conditions of Use:
Read the Fine Print
Rating

An interactive applet and associated web page that demonstrate the exterior angles of a triangle. The applet shows a triangle where the user can drag any vertex to reshape it. The exterior angles are shown and a running calculation shows that no matter how you change the triangle, the exterior angles always add up to 360 degrees An exterior angle is equal to the sum of the opposite interior angles Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

Subject:
Geometry
Material Type:
Reading
Simulation
Provider:
Math Open Reference
Author:
John Page
Date Added:
02/16/2011
Triangle inequality
Conditions of Use:
Read the Fine Print
Rating

An interactive applet and associated web page that demonstrate the concept of triangle inequality. The applet shows a triangle where the vertices can be dragged to reshape the triangle It shows that no matter what you do, the longest side is always shorter than the sum of the other two. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

Subject:
Geometry
Material Type:
Reading
Simulation
Provider:
Math Open Reference
Author:
John Page
Date Added:
02/16/2011
Triangles Everywhere: Sum of Angles in Polygons
Conditions of Use:
Read the Fine Print
Rating

Students learn about regular polygons and the common characteristics of regular polygons. They relate their mathematical knowledge of these shapes to the presence of these shapes in the human-made structures around us, especially trusses. Through a guided worksheet and teamwork, students explore the idea of dividing regular polygons into triangles, calculating the sums of angles in polygons using triangles, and identifying angles in shapes using protractors. They derive equations 1) for the sum of interior angles in a regular polygon, and 2) to find the measure of each angle in a regular n-gon. This activity extends students’ knowledge to engineering design and truss construction. This activity is the middle step in a series on polygons and trusses, and prepares students for the Polygon and Popsicle Trusses associated activity.

Subject:
Mathematics
Geometry
Material Type:
Activity/Lab
Provider:
TeachEngineering
Author:
Andi Vicksman
Maia Vadeen
Malinda Zarske
Nathan Coyle
Russell Anderson
Ryan Sullivan
Sabina Schill
Date Added:
02/07/2017