Question

The area of the base of a right circular cylinder is 616 cm² and its height is 2.5 cm. Find the curved surface area of the cylinder.

 

Answer 1

\[\text{ Given } : \]
\[ \text{ Area of the base of a right circular cylinder = 616 {cm} }^2 \]
\[\text{ Height } = 2 .5 cm \]
\[\text{ Let r be the radius of the base of a right circular cylinder }  . \]
\[ \pi r^2 = 616\]
\[ \Rightarrow r^2 = 616 \times \frac{7}{22}\]
\[ \Rightarrow r^2 = 196\]
\[ \Rightarrow r = 14 cm\]
\[\text { Curved surface area of the right circular cylinder }  = 2\pi rh = 2 \times \frac{22}{7} \times 14 \times 2 . 5 = 220 {cm}^2 \]