tolong bantu jawab nomor 25 dan 30

25) K= 2πr
22=2x3,14xr
22=6,28r
r=22/6,28= 3,5

L=πxr^2
=3,14x(3,5)^2
=3,14x12,25 = 38,5 cm^2 (B)

30) V= πxr^2xt
r=7/2=3,5

jadi, V=3,14x(3,5)^2x15
=3,14x12,25x15
=577,5 (C)