Question:
The area of the base of a right circular cylinder is 616 cm2 and its height is 25 cm. Find the volume of the cylinder.
Solution:
Let the area of the base of a right circular cylinder be $S \mathrm{~cm}^{2}$.
Given :
$S=616 \mathrm{~cm}^{2}$
Height, $h=25 \mathrm{~cm}$
Let the radius of a right circular cylinder be $r \mathrm{~cm}$.
$S=\pi r^{2}$
$616=\frac{22}{7} \times \mathrm{r}^{2}$
$\mathbf{r}^{2}=\frac{616 \times 7}{22}$
$\mathrm{r}^{2}=196$
r = 14 cm
Volume of the cylinder, $\mathrm{V}=\pi r^{2} h$
$=\pi \times(14)^{2} \times 25$
$=15400 \mathrm{~cm}^{3}$