Question

If a rectangular sheet of paper $40cm\times 22cm$ is rolled to form a hollow cylinder of height $40cm$, then find the radius of the cylinder.

Answer 1

According to question,

Height of cylinder = $40cm$

Let radius of cylinder be $r$

And circumference of base $=22cm$

$\Rightarrow$ $2\pi r=22cm$

$\Rightarrow$$2.\frac{22}{7}.r=22$

$\Rightarrow$ $r=\frac{7}{2}cm$

Hence , radius =$3.5cm$