We know that the length of the rectangle is five times the width, so: l = 5w Where l is length and w is width. We also know that the perimeter is 84 cm, so: 2l + 2w = 84 Now we can plug in 5w for l since we found the equality earlier: 2(5w) + 2w = 84 and then solve for w: 10w + 2w = 8412w = 84w = 7 Now we know the width is 7 cm. Since the length is 5 times the width, the length is 35, and the area of the rectangle is 7 x 35 = 245 cm2. Hope this helps