tolong dgn caranya harus benar besok dikumpul

π.r².t
22/7×10.5×10.5×18
=7.276.5cm³

1.v=πr²t (untuk nomer 2 dst saya gk nulis rumusnya)
=22/7 10,5*10,5*18
=22/7*110,25*18
=176/7*110,25=19404/7=2772
2.v=3,14*20*20*27
=3,14*400*27
=1256.27=33912
3.9240=22/7*7*7*t
9240=154t (7dibagi7 lalu 22 dikali 7)
t=9240/154=60
4.2826=3,14*r²*9
2826/9=3,14*r²
314=3,14*r²
r²=314/3,14
r²=100
r=10