length = 2(width)
perimeter = 36 cm
using variables where x = width and y = length
Perimeter = 2x + 2y = 36 cm
y = 2x
solving for length 2x + 2(2x) = 36 cm
2x + 4x = 36 cm
6x = 36 cm
x = 6 cm
so y = 2(6 cm) = 12 cm
area of rectangle = 12 cm * 6 cm = 72 cm^2