Question

A farmer wants to use 200 feet of fencing for a chicken pen. He wants the width of the pen to be 20 feet. What is the length of the pen? Please tell me step by step how you got the answer. thanks

Answer 1

Perimeter = 200 feet
Perimeter = l + l + w + w or l(2) × w(2)

Since you know that the width is 20 feet and there are 2 sides that are the width, you could say he already used 40 feet of fencing. Next you subtract 40 from 200 feet to get 160. So he has 160 feet of fencing left. Since there are two sides left which are equal you divide 160 by 2 to get 80. So the length is 80 feet.

Answer: 80 feet

Answer 2

The width is 20, and there are two sides that are the width.

So in doing the width he's already used 20 + 20 = 40 feet of fencing.

200 - 40 = 160

We have 160 left for the length, and there are also two sides for the length, so we divide by 2.

160 / 2 = 80

So the length of the pen is 80 feet.