Question

The volume of a cylinder is $98\pi$cu.cm and its height is $8$cm.Find its lateral surface area.

Answer 1

Volume of a cylinder$=98\pi$cu.cm

$\Rightarrow \pi r^{2}h=98\pi$cu.cm

$\Rightarrow \pi r^{2}h=98\pi$ .......$\left(1\right)$

Given:$h=8$

$\left(1\right)\Rightarrow \pi r^2\times 8=98\pi$

$\Rightarrow r^2=\frac{49}{4}$

$\Rightarrow r=\frac{7}{2}=3.5$cm

$\therefore$ Lateral surface area$=2\pi rh$

$=2\times \frac{22}{7}\times 3.5\times 8$

$=22\times 8=176$sq.cm