# Lesson 14 Find the Area of Figures with Missing Sides

Let’s find the area of figures with missing side lengths.

## Warm-up Notice and Wonder: Mystery Sides

What do you notice? What do you wonder?

## Activity 1 The Mystery Side

Tyler says that the missing side length is 5 meters because it looks longer than the sides that are 4 meters long.

Do you agree or disagree? Be prepared to explain your reasoning.

## Activity 2 Practice with Mystery Sides

Find the area of each figure. Explain or show your reasoning.

## Practice Problem

## Problem 1

Find the area of this figure. Explain or show your reasoning.