Sprendimas: kDhHe5 - 1

S =
π

* (R+r)* l+ π

* R^²+ π

* r^²

S = π

* (R+r)* l+ π

* R^²+ π

* r^² $S$ = $\pi\cdot (R+r)\cdot l+\pi\cdot R^{2}+\pi\cdot r^{2}$

S = R* l* π

+ r* l* π

+ R^²* π

+ r^²* π

$S$ = $R\cdot l\cdot \pi+r\cdot l\cdot \pi+R^{2}\cdot \pi+r^{2}\cdot \pi$

S = R* l* π

+ l* r* π

+ R^²* π

+ r^²* π

$S$ = $R\cdot l\cdot \pi+l\cdot r\cdot \pi+R^{2}\cdot \pi+r^{2}\cdot \pi$