Let L be the length and W be the width. "the width of a rectangle is half as long as the length" W = (1/2)·L "the rectangle has an area of 18 square feet" A = L·W = 18 Substitute, L·W = 18 L·(1/2)·L = 18 (L²)/2 = 18 L² = 36 L = 6 feet then W = (1/2) · L W = (1/2) · 6 W = 3 feet
