Question

The height of a circular cylinder is $20cm$ and the diameter of its base is $14cm$. Find:
(i) its volume
(ii) its total surface area

Answer 1

Given :

Diameter$=14cm$

Therefore, Radius $=\frac{14}{2}=7cm$

Height $\left(h\right)=20cm$

Therefore, Volume $=\pi r^{2}h=\pi (7{)}^2\times 20$

$=\frac{22}{7}\times 7\times 7\times 20$

$=22\times 7\times 20$

$=3080c{m}^3$

Now,

T.S.A $=2\pi r(r+h)=2\pi \times 7(7+20)$

$=2\times \frac{22}{7}\times 7\times 27$

$=2\times 22\times 27$

$=1188c{m}^2$

Hence, volume of the cylinder is $3080c{m}^3$ and the TSA is $1188c{m}^2$.