Aidan has 20 ft of fence with which to build a rectangular dog run. What is the maximum area he can enclose? Enter your answer in the box.

Maximum area is 25 m²

Explanation:

Let L be the length and W be the width.

Aidan has 20 ft of fence with which to build a rectangular dog run.

Fencing = 2L + 2W = 20 ft

L + W = 10

W = 10 - L

We need to find what is the largest area that can be enclosed.

Area = Length x Width

A = LW

A = L x (10-L) = 10 L - L²

For maximum area differential is zero

So we have

dA = 0

10 - 2 L = 0

L = 5 m

W = 10 - 5 = 5 m

Area = 5 x 5 = 25 m²

Maximum area is 25 m²