Arectangle is 4 times as long as it is wide. if the area is 100 square feet, find its perim

Let the width be x.

Length = 4x

Area = 100 sq. feet

lw = 100

4x * x = 100

4x² = 100

(2x)² = (10)²

2x = 10

x = 5

Therefore,

Length = 4 * 5 = 20 ft

Width = 5 ft

Hence, 

Perimeter = 2(l + w) = 2(20 + 5) = 2 * 25 = 50 ft

Hence, the perimeter is 50 ft.

The percent increase is 25%