# Lesson 8 Find the Perimeter

Let’s find the perimeter of more shapes.

## Warm-up Number Talk: Decreasing Dividend

Find the value of each expression mentally.

## Activity 1 Ways to Find Perimeter

## Problem 1

What do you notice? What you wonder?

## Problem 2

Find the perimeter of each shape. Explain or show your reasoning.

## Activity 2 Something is Missing

Find the perimeter of this rectangle. Explain or show your reasoning.

All the short sides of this figure are the same length, and all the angles are right angles. Find the perimeter. Explain or show your reasoning.

All the sides of the octagon are the same length. Find the perimeter. Explain or show your reasoning.

## Practice Problem

## Problem 1

Find the perimeter of each shape. Explain or show your reasoning.