If x and y are the dimensions under the question, then from the condition you have these two equations 2x + y = 320 yards (1) 2x + 2y = 400 yards (2) Subtract eq(1) from eq(2). You will get y = 400-320 = 80 for one dimension (y). Then for x you have from eq(1) 2x + 80 = 320 ====> 2x = 320-80 = 240 ====> x = 240/2 = 120. ANSWER. The dimensions are 120 and 80 yards. 80 yards go along the wall. 120 yards go perpendicularly to the wall.