Explicație pas cu pas:
3.Al=12πcm²
Ab=2πcm²
Atotală=12π+2×2π=16πcm²
4.r=4cm h=8cm
V=πr²h=π4²×8=128πcm³
At=πr²×2+(2πr×h)=2×16π+2π4×8=32π+64π=96πcm²
5.Vcon=πr²h/3=42πcm³
r=3cm
π9h/3=42π
3h=42
h=14cm
Al=2πrh=2π3×14=84cm²
