Question

The volume of a right circular cylinder is 4224 cm^3. Its height is 21 cm. Find the total surface of the cylinder.​

Answer 1

$\sf \: Volume\:=\:4224\:cm^3 \\ \\ \sf Height\:=\:21\:cm$

So,

$\large \sf \: Radius\:=\: \sqrt{ \frac{v}{\pi \: h} }$

$\sf\large\: Radius\:=\: \sqrt{ \frac{4224}{3.14 \: \times \: 21} } \: \: \: \: \: \: \: \: \: \: \: \color{aqua}{ \underline{Taking\:\pi\:as\:3.14}}$

$\sf \: Radius\:= \: 8.12 \: cm \: (approx)$

Total Surface Area :-

$\sf \: 2 \: \pi \: r \: (h \: + \: r)$

Substituting the values,

$2 \: \times \: \frac{22}{7} \: \times \: 8.12 \: (21 \: + \: 8.12)$

$\sf \: 2 \: \times \: \frac{22}{7} \: \times \: 170.52 \: + \: 85.9344$

$\sf \: \therefore \: Total\:Surface\:Area\:=\:1084.11634285714\:sq.cm$