someone help me !! no 8

luas kulit genderang = 3,14x40x40 = 5.024 cm dikali 2 = 1.048 cm
luas rangka = keliling genderang x 50cm
= 3,14 x 80 x 50 = 12.560cm
luas genderang = 1.048 + 12.560 = 13.608 cm