Question

Find the curved surface area and total surface area of a cylinder, the diameter of whose base is 7 cm and height is 60 cm.

 

Answer 1

\[\text{ Let r and h be the radius and the height of the cylinder }  . \]
\[\text{ Given: } \]
\[r = \frac{7}{2} \text{ cm } \]
\[h = 60 \text{ cm } \]
\[\text{ Curved surface area of the cylinder } = 2\pi \times r \times h\]
\[ = 2 \times \frac{22}{7} \times \frac{7}{2} \times 60\]
\[ = 22 \times 60 = 1320 {cm}^2 \]
\[\text{ Total surface area of the cylinder } = 2\pi \times r \times (r + h)\]
\[ = 2 \times \frac{22}{7} \times \frac{7}{2} \times (\frac{7}{2} + 60) = 22 \times \frac{127}{2} = 11 \times 127 = 1397 {cm}^2\]