Question 156578
length = 2 * w.

if w = width then l = length = 2w.

p = perimeter = 48 cm.

perimeter = 2*l + 2*w.

since l = 2w, then perimeter = 2*(2w) + 2*w.

4w + 2w = 6w = 48, so w = 48/6 = 8 cm.

if w = 8 cm, then l = 2w = 16 cm.

area of a rectangle is length * width = 8 * 16 = 128 cm.