# 3.MD.C.7d- Finding the Area of Rectilinear Figure_Parts of a Pool

## 3.MD.C.7d  Finding the Area of  Rectilinear Figures

### Parts of a Pool

The county is building a new pool. The pool has a width of 11 meters. The length of the lap pool is 3 meters more than the diving and shallow areas.

This rectilinear image shows a swimming pool with three distinct swimming sections. There is a lap pool, a diving section and a shallow section. The lap pool is 5 meters wide and 17 meters long. The diving section is 8 meters long and 6 meters wide. The shallow section is 9 meters long and 6 meters wide.

• What is the area of the lap pool? Show your work.
• What is the area of the diving section? Show your work.
• What is the area of the shallow section? Show your work.
• What is the total area of the pool? Show your work.

## Scoring Rubric

### Score 4

Student response includes the following 4 elements.

Reasoning component = 4 points

• The area of the lap pool with supporting work
• The area of the diving section with supporting work
• The area of the shallow section with supporting work
• The total area with supporting work

Sample Student Response:

The area of the lap pool is 20 × 5 = 100 square meters.

The area of the diving section is 8 × 6 = 48 square meters.

The area of the shallow area is 9 × 6 = 54 square meters.

When you add them together to get the area of all three parts of the pool you get 202 square meters because 100 + 48 + 54 = 202 (or similar explanation).

Note: When labels are not presented, the elements are scored in the same order as the prompt. The lap pool is addressed first, the diving section next, the shallow section after that, and the total last.

### Score 3

Student response includes 3 of the 4 elements.

### Score 2

Student response includes 2 of the 4 elements.

### Score 1

Student response includes 1 of the 4 elements.

### Score 0

Student response is incorrect or irrelevant.