# If the diameter of a cylinder is 28 cm and its height is 20 cm

Question:

If the diameter of a cylinder is 28 cm and its height is 20 cm, then its curved surface area is
(a) 880 cm2
(b) 1760 cm2
(c) 3520 cm2
(d) 2640 cm2

Solution:

(b) $1760 \mathrm{~cm}^{2}$

Curved surface area of the cylinder $=2 \pi r h$

$=2 \times \frac{22}{7} \times 14 \times 20$

$=44 \times 40$

$=1760 \mathrm{~cm}^{2}$