(1): \(C_{đáy}=\left(5+2\right)\cdot2=14\left(cm\right)\)
\(S_{XQ}=14\cdot3=42\left(cm^2\right)\)
\(S_{TP}=42+2\cdot5\cdot2=62\left(cm^2\right)\)
(2): R=2,2:2-0,8=1,1-0,8=0,3(m)
\(S_{XQ}=\left(0.3+0.8\right)\cdot2\cdot0.5=1.1\left(m^2\right)\)
\(S_{TP}=1.1+2\cdot0.8\cdot0.3=1.58\left(m^2\right)\)
(3): C=(4/5+1/2)*2=13/5(m)
Sxq=13/5*2/3=26/15(m2)
Stp=26/15+2*4/5*1/2=38/15m2