Question

Find the height of the cylinder whose radius is $21cm$ and total surface area is $968c{m}^2$.

Answer 1

Now, we know that,

Total Surface Area of Cylinder $=2\pi rh+2\pi r^2=2\pi r(r+h)$

Here, Radius ($r$) $=21cm$

Now, according to the question,

$\Rightarrow 2\pi r(r+h)=968$

$\Rightarrow 2\times \frac{22}{7}\times 7(7+h)=968$

$\Rightarrow 7+h=968\times \frac{1}{44}$

$\Rightarrow h=22-7=15cm$

Hence, height of the cylinder is $15cm$.