Question

The surface area of a sphere of radius 5 cm is 5 times the area of curved surface of a cone of radius 4 cm. Find the height and the volume of cone.

Answer 1

$4\Pi (5{)}^2=5\times \Pi (4)\times l$
l=5cm
l= square root of $(r^2+h^2)=5$
square root of $(4^2+h^2)=5$
$16+h^2=25h^2=9$
h=3cm
Volume of a cone can be found out using the $V=\left(\frac{1}{3}\right)\Pi r^{2}h$