### Home > CCAA > Chapter 7 Unit 9 > Lesson CC3: 7.2.5 > Problem 7-86

Mr. Crow, the head groundskeeper at High Tech Middle School, mows the lawn along the side of the gym. The lawn is rectangular, and the length is

Define a variable and write an equation for this problem.

Recall that the equation of a perimeter is

. Use the information to make an equation for the perimeter with only one variable and set it equal to , which is the given perimeter. Let

represent the width of the lawn:

. Solve the equation that you wrote in part (a) and find the dimensions of the lawn.

Start by distributing the two to the terms in parentheses and solve from there for

.

Once you find, substitute it into an equation for:. Use the dimensions you calculated in part (a) to find the area of the lawn.

The area of a rectangle is

.