Question

the curved surface area of a cylinder is 440 cm². Find its volume if the height of it is 21cm​

Answer 1

reffer to the attachment

Answer 2

★ Given :-

• CSA of cylinder = 440 cm²
• Height = 21 cm

★ To find :-

♦ Volume = ?

★ Solution :-

We know that;

$\bf{CSA \: of \: cylinder = 2\pi \: rh}$

$\implies \sf{440 = 2 \times \dfrac{22}{7} \times r \times 21}$

$\implies \sf{440 = \dfrac{924r}{7} }$

$\implies \sf{r = \dfrac{440 \times 7}{924} }$

$\therefore \boxed{ \sf{r = 3.3}}$

$\bf{Volume \: of \: cylinder = \pi {r}^{2} h}$

$\implies \sf{Volume = \dfrac{22}{7} \times 3.3 \times 3.3 \times 21}$

$\implies \sf{Volume = 22 \times 3.3 \times 3.3 \times 21}$

$\therefore \large{ \boxed{ \bf{Volume = 718.74 \: cm {}^{3} }}}$

Know more:

→ CSA or Curved surface area is the area of the 3D figure excluding top and bottom area.

→ Volume is the quantity of substance that the substance can hold