mohon bantuan ya thanks

18. V : phi x r x r
: 22/7 x 14 x 14
: 616 CM (kubik)

18. L = phi x d
= 22/7 x 28
= 88 cm2

19. L = 1/4 x phi x d
= 1/4 x 3,14 x 20
= 15,7 cm2