Question

A rectangular sheet of metal $44$cm long and $20$cm broad is rolled along its length into a cylinder.Find the curved surface area of the cylinder.

Answer 1

Length of the sheet$=$Circumference of the base.

$\Rightarrow 44=2\pi r$

$\Rightarrow r=44\times \frac{1}{2}\times \frac{7}{22}=7$

$\therefore$ Radius$=7$cm

Breadth of the metal sheet$=$height of the cylinder

$h=20$cm

Curved surface area$=2\pi rh$

$=2\times \frac{22}{7}\times 7\times 20=880$sq.cm

$\therefore$ Curved surface area is $880$sq.cm