Question

Find, correct to three significant figures, the radius of the base of a circular cone whose height is 5 cm and volume 12 cm³.

Answer 1

$$\begin{gathered} \mathrm{Hi}, \\ \mathrm{volume}\mathrm{of}\mathrm{cone} \\ \frac{1}{3}\times {\mathrm{\pi r}}^2\mathrm{h}=12 \\ \frac{1}{3}\times \frac{22}{7}\times {\mathrm{r}}^2\times 5=12 \\ {\mathrm{r}}^2=\frac{12\times 21}{110}=2.29 \\ \mathrm{r}=\sqrt{2.29}=1.513\mathrm{cm} \\ \mathrm{Regards} \end{gathered}$$