1.底面半径是3厘米,高是5厘米.2.底面周长是12.56分米,高是6分米.

8533125969696,
1、V=1/3×πr^2
=3×3×3.14×5×1/3
=15×3.14
=47.1立方厘米
2、L=2πr
r=L÷2π
=12.56÷2÷3.14
=2厘米
V=1/3×πr^2
=2×2×3.14×6×1/3
=8×3.14
=25.12立方厘米