Question

If the lateral surface of a cylinder is $94.2{cm}^2$ and its height is $5cm$, then find
(i) radius of its base
(ii) its volume. (Use $\pi =3.14)$.

Answer 1

Lateral surface area of cylinder $=94.2$ cm² (given)

height $=5$ cm

Lateral surface area $=2\pi rh$

=> $94.2=2\times 3.14\times r\times 5$

=> $94.2=31.4\times r$

=>$\left(94.2\right)÷\left(31.4\right)=r$

=> $3=r$

thus radius $=3$ cm

Now,

Volume $=\pi r²h$

$=3.14\times \left(3\right)²\times 5$

$=141.30$cm³

thus volume $=141.30$ cm³