# Lesson 3

Lots of Rectangles

- Let’s express the areas of some rectangles.

### 3.1: Math Talk: Many Ways to Area

A rectangle is partitioned into smaller rectangles. Explain why each of these expressions represents the area of the entire rectangle.

\(7(7+7+4+4)\)

\(7(2 \boldcdot 7 + 2 \boldcdot 4)\)

\(7^2+7^2+4 \boldcdot 7+4 \boldcdot 7\)

\(2(7^2) + 2 (4 \boldcdot 7)\)

### 3.2: Representing Areas

- \(2 \boldcdot 3^2\)
- \(6n^2\)
- \(n^2+1^2\)
- \(3^2\)

- \((n+1)(n+1)\)
- \((2n)(3n)\)
- \((n+1)^2\)
- \(3(3+3)\)

- \(n^2\)
- \((n+n)(n+n+n)\)
- \(3^2+3^2\)

### 3.3: Areas of Rectangles

Complete the table with the length, width, and area of each rectangle.

rectangle | length (units) | width (units) | area (square units) |
---|---|---|---|

A | \(a+4\) | ||

B | 2 | ||

C | |||

D | |||

E |