Question

A rectangular piece of paper of width 20 cm and length 44 cm is rolled along its width to form cylinder. What is the volume of the cylinder so formed?

Answer 1

The length of the rectangle becomes the circumference of the base of the cylinder.

$\therefore 2\pi r=44,$, where r is the radius of the cylinder.

$\therefore r=\frac{44\times 7}{2\times 22}=7cm$
The width of the rectangle becomes the height of the cylinder.

$\therefore$ Volume $=\pi r^{2}h=\frac{22}{7}\times 7\times 7\times 20c{m}^3=3080c{m}^2$