Let x be the length, y be the width and p be the perimeter. p = 2x + 2y Since the length is 3 times the width x = 3y So, 2400 = 2(3y) + 2y 2400 = 6y + 2y 2400 = 8y y = 300 Now plug y back in, x = 3(300) x = 900 The length is 900 ft and the width is 300 ft