Sagot :
[tex]A_S=2\pi r^2+2\pi rH\\\\r=2cm;\ H=3cm\\\\A_S=2\pi\cdot2^2+2\pi\cdot2\cdot3=2\pi\cdot4+2\pi\cdot6=8\pi+12\pi=20\pi\ (cm^2)\\\\20\pi\approx20\cdot3.14=62.8\ (cm^2)[/tex]
[tex]S=2\pi r(r+h)\\
S=2\cdot3.14\cdot2\cdot(2+3)\\
S=12.56\cdot5\\
S=62.8\ cm^2[/tex]