A farmer builds a rectangular pen with a perimeter of 116 feet. If the length is 5 feet more than the width, what is the width?

The formula for the perimeter of a rectangle is:

A=2l+2w.

We know the area is 116, so we can plug that in for A. Now, we cant solve the equation yet because it still has two variables. Since we know the length is 5 feet greater than the width, we can rewrite l in terms of w. So here is what our new equation will look like:

116=2 (w+5) + 2w

Now lets solve:

116=2w+10+2w

106=4w

w=26.5 ft.

The width is 26.5 ft.