Answer:
A = 8 miles^2
Explanation:
The perimeter of a rectangle is given by
P = 2(l+w)
Substitute the knowns in
12 = 2(l+4)
Divide each side by 2
12/2 = 2/2(l+4)
6 = l+4
Subtract 4 from each side
6-4 = l+4-4
2 =l
The length is 2 and the width is 4
We want to find the area
A = l*w
= 2miles * 4 miles
= 8 miles^2