Question

The radius and the lateral surface area of right circular cone are 8 cm and 220 sq cm respectively . Find slant height of cone

Answer 1

$$\begin{gathered} \mathrm{Let}\mathrm{the}\mathrm{slant}\mathrm{height}\mathrm{of}\mathrm{the}\mathrm{cone}=\mathrm{l} \\ \mathrm{Now},\mathrm{radius}\mathrm{of}\mathrm{base}\mathrm{of}\mathrm{cone},\mathrm{r}=8\mathrm{cm} \\ \mathrm{CSA}=220{\mathrm{cm}}^2 \\ \Rightarrow \mathrm{\pi rl}=220 \\ \Rightarrow \frac{22}{7}\times 8\times \mathrm{l}=220 \\ \Rightarrow \mathrm{l}=\frac{70}{8}=8.75\mathrm{cm} \end{gathered}$$