30. CHỌN (B). S = 4 Π R2 = 4 Π 52 =4 Π .25 =100 Π CM2.V= 43 Π R3 = ..
4.30. Chọn (B). S = 4
π
r
2
= 4
π
5
2
=4
π
.25 =100
π
cm
2
.
V=
4
3
π
r
3
=
4
3
π
5
3
=
500
3
π
com
3
.
4.30. Chọn (B). S = 4
π
r
2
= 4
π
5
2
=4
π
.25 =100
π
cm
2
.
V=
4
3
π
r
3
=
4
3
π
5
3
=
500
3
π
com
3
.