Answer:
The dimension that maximizes area is 144ft by 144ft
Explanation:
Given
-- perimeter
Required
The dimension that gives maximum area
Perimeter is calculated as:

So, we have:

Divide through by 2

Make L the subject

Area is calculated as:

Substitute


Open bracket

Differentiate A with respect to W

Set to 0 to calculate W

Collect like terms

Divide by 2

Recall that:


