Question

If the diameter of a cylinder is 28 cm and its height is 20 cm, then its curved surface area is
(a) 880 cm²
(b) 1760 cm²
(c) 3520 cm²
(d) 2640 cm²

Answer 1

(b) 1760 cm²

$$\begin{gathered} \mathrm{Curved}\mathrm{surface}\mathrm{area}\mathrm{of}\mathrm{the}\mathrm{cylinder}=2\mathrm{\pi rh} \\ =2\times \frac{22}{7}\times 14\times 20 \\ =44\times 40 \\ =1760{\mathrm{cm}}^2 \end{gathered}$$