You want to build a rectangular fence for a garden. The perimeter is 200 feet. The length is twenty more than the width. What is the length and width of your fence?

Question

You want to build a rectangular fence for a garden. The perimeter is 200 feet. The length is twenty more

than the width. What is the length and width of your fence?

Answer 1

Hello Jayleen,

The formula for a rectangle's perimeter is P = 2 (L +W)

Let's start using the info given in the problem. P = 200 ---> 200 = 2(L +W)

Divide by 2 on both sides: 100 = L +W

Length is 20 more than the width ---> L = W +20, plug that formula in the previous one and you get:

100 = W + 20 + W ---> 100 = 2W + 20

Subtract 20 on both sides: 80 = 2W

Divide by 2: 40 = W

If the width is 40 feet and the length is 20 more, then the length is 40 + 20 = 60 feet

Check: perimeter = 2(60 + 40) = 2 (100) = 200 which is the perimeter given in the problem statement

Answer: the length is 60 feet and the width is 40 feet.