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daily12000-01-01T12:00+00:00Geometry Module 2: Similarity, Proof, and Trigonometry
https://www.oercommons.org/courses/geometry-module-2-similarity-proof-and-trigonometry
Just as rigid motions are used to define congruence in Module 1, so dilations are added to define similarity in Module 2. To be able to discuss similarity, students must first have a clear understanding of how dilations behave. This is done in two parts, by studying how dilations yield scale drawings and reasoning why the properties of dilations must be true. Once dilations are clearly established, similarity transformations are defined and length and angle relationships are examined, yielding triangle similarity criteria. An in-depth look at similarity within right triangles follows, and finally the module ends with a study of right triangle trigonometry.Geometry2016-05-26T16:49:01.063327Course Related MaterialsGeometry Deductive Proof Relay
https://www.oercommons.org/authoring/12083-geometry-deductive-proof-relay
Students engage in a competitive group relay to construct formal proofs involving triangles.
New proofs can always be written to fit different curriculum and pacing. Chariya FisherMathematics2016-02-12T12:52:53.049663Open Author MaterialsBuilding with Triangles
https://www.oercommons.org/courses/building-with-triangles-2
This 3 lesson instructional unit helps students investigate many different aspects of triangles including basic properties of triangles, building other shapes from triangles, the dependence of the third side length on the other two (Triangle Inequality Theorem), and the Sierpinski Triangle fractal. The lesson includes student activity sheets and links to interactive applets.Marea W. ChannelEducationMathematicsGeometry2016-02-07T21:36:24.258733Course Related Materials