# Lesson 9

Polygons

Let’s investigate polygons and their areas.

### Problem 1

Select all the polygons.

A:

A

B:

B

C:

C

D:

D

E:

E

F:

F

### Problem 2

Mark each vertex with a large dot. How many edges and vertices does this polygon have?

### Problem 3

Find the area of this trapezoid. Explain or show your strategy.

### Problem 4

Lin and Andre used different methods to find the area of a regular hexagon with 6-inch sides. Lin decomposed the hexagon into six identical, equilateral triangles. Andre decomposed the hexagon into a rectangle and two triangles.

Find the area of the hexagon using each person’s method. Show your reasoning.

### Problem 5

1. Identify a base and a corresponding height that can be used to find the area of this triangle. Label the base $$b$$ and the corresponding height $$h$$.

2. Find the area of the triangle. Show your reasoning.

(From Unit 1, Lesson 8.)

### Problem 6

On the grid, draw three different triangles with an area of 8 square units. Label the base and height of each triangle.

(From Unit 1, Lesson 8.)