a)
P1 = 3 * 3 = 9cm^2
P2 = 4 *2 = 8cm^2
P3 = 4 * 3 = 12cm^2
P4 = 8 * 3 = 24cm^2
P = 9 + 8 + 12 + 24 = 53cm^2
b)
P1 = 10 * 6 = 60cm^2
P2 = 3 * 4 = 12cm^2
P3 = 6 * 6 = 36cm^2
P = 60 + 12 + 36 = 108cm^2
