Question

Find the volume and curved surface area of a right circular cylinder of height 21 cm and base radius 5 cm.

Answer 1

Here, r = 5 cm; h = 21 cm

$$\begin{gathered} \mathrm{Volume}\mathrm{of}\mathrm{the}\mathrm{cylinder}=\mathrm{\pi }{r}^{\mathit{2}}h\mathit{} \\ =\frac{22}{7}\times 5^2\times 21{\mathrm{cm}}^3 \\ =22\times 25\times 3 \\ =1650{\mathrm{cm}}^3 \end{gathered}$$

$$\begin{gathered} \therefore \mathrm{Curved}\mathrm{surface}\mathrm{area}\mathrm{of}\mathrm{the}\mathrm{cylinder}=2\mathrm{\pi }rh \\ =2\times \frac{22}{7}\times 5\times 21{\mathrm{cm}}^2 \\ =2\times 22\times 5\times 3{\mathrm{cm}}^2 \\ =660{\mathrm{cm}}^2 \end{gathered}$$