Question 70321
P = 2L + 2W
Substitute in the known values of perimeter and width.
18 = 2L + 2*5
18 = 2L + 10
Subtract 10 from each side of the equation
18 - 10 = 2L + 10 - 10
8 = 2L
Divide each side by 2 to get
4 = L
ie the length is 4 feet.