Question

A rectangular piece of paper 22 cm long and 12 cm wide is rolled along the length to form a cylinder of height 12 cm. Find the volume of the cylinder so formed.

Answer 1

Solution.

A rectangular piece of paper 22 cm long and 12 cm wide is rolled along the length to form a cylinder of height 12 cm

therefore......

height (h)=12cm

radius=r(let).

now.. perimeter=22 cm

therefore...2πr=22

=>r=(11×7/22)=7/2 =3.5 cm

therefore.. volume

$= (\frac{22}{7} \times ( \frac{7}{2} ) {}^{2} \times 12) \: cm {}^{3} \\ = (22 \times 7 \times 3)cm {3}^{2} \\ = 462 \: cm {}^{3}$