If the area of parallelogram ABCD is 100, then s △ PAB + s △ PCD =

If the area of parallelogram ABCD is 100, then s △ PAB + s △ PCD =

If the vertical line of AB crosses E and F through P, then s △ PAB + s △ PCD = 1 / 2 * AB * PE + 1 / 2 * CD * pf = 1 / 2 * AB * (PE + PF) = 1 / 2 * AB * H = 1 / 2 * s (ABCD) = 1 / 2 * 100 = 50