The radius of a cone is 5 cm and vertical height is 12 cm. Find the area of the curved surface.
Radius of cone (r) = 5 cm
Vertical height (h) = 12 cm
Slant height of cone (l) = √(r2+h2) = √(52+122) = √25+144 = √169 = 13 cm
Curved surface area of cone = πrl = 22/7×5×13 = 204.28 cm2