Question

The curved surface area of a cylinder is 1320 $c{m}^2$ and its base had diameter 21 cm. Find the height and the volume of the cylinder. [Use $\pi$ = 22/7]

Answer 1

Curved surface area of a cylinder = 1320 $c{m}^2$

Diameter of the base = 21 cm

$\therefore Radius=\frac{21}{2}$ cm

Now 2$\pi rh=1320c{m}^2$

$\Rightarrow \frac{2\times 22}{7}\times \frac{21}{2}h$ = 1320

$\Rightarrow 66h=1320\Rightarrow h=\frac{1320}{66}=20$

$\therefore$ Height = 20 cm

and volume = $\pi r^2$ h

= $\frac{22}{7}\times \frac{21}{2}\times \frac{21}{2}\times 20c{m}^3=6930c{m}^3$