H = R + 10 или
S полн = 2S осн + S бок = 144 см^2
S осн = pi *R^2
S бок = С * H = (2pi*R) * H = (2pi*R) * (R + 10) = 2pi *R^2 + 20pi *R
=>
(2 *pi*R^2) + (2pi *R^2 + 20pi*R) = 144
4pi*R^2 + 20pi*R - 144 = 0
piR^2 + 5pi*R - 36 = 0
3,14*R^2 + 15,7R - 36 = 0