Remember that the perimeter of a rectangle is given by the formula:
P = 2L + 2W
where P is the perimeter
L is the length
W is the width
given : P=36ft
L = 10ft
substituting the given values to the formula you'll have:
P = 2L + 2W
36 = 2(10) + 2W
36 - 20 = 2W
2W = 16
W = 8
