Question

A rectangular piece of paper 11 cm × 4 cm is folded without overlapping to make a cylinder of height 4 cm. Find the volume of the cylinder.

Answer 1

Length of the paper becomes the perimeter of the base of the cylinder and

width becomes height.

Let radius of the cylinder = r and height = h

Perimeter of the base of the cylinder = 2πr = 11

or ${\displaystyle 2\times \frac{22}{7}\times r=11}$

Therefore,

r = ${\displaystyle \frac{7}{4}}$ cm

Volume of the cylinder = V = πr²h

= ${\displaystyle \frac{22}{7}\times \frac{7}{4}\times \frac{7}{4}\times 4}$ cm³

= 38.5 cm³

Hence the volume of the cylinder is 38.5 cm³.