Question

Find the curved surface area and the total surface area of a right circular cylinder whose height is 15 cm and the diameter of the cross-section is 14 cm.

Answer 1

Diameter of the base of cylinder = 14
$\therefore$ Radius (r) $=\frac{14}{2}cm=7cm$
Height (h) = 15 cm

$\therefore$ Curved surface area $=2pirh$
$=2\times \frac{22}{7}\times 7\times 15=660c{m}^2$
Total surface area $=2\pi r(h+r)$
$=2\times \frac{22}{7}\times 7(15+7)$
$=2\times \frac{22}{7}\times 7\times 22=968c{m}^2$