Question

The diameter of a roller is $70cm$ and length is $2m$. Find the area in square metres covered by the roller in $50$ complete rounds.

Answer 1

Given: Diameter of the circle$=70cm$

Radius = $\frac{70}{2}=35cm=0.35m$

Height of the roller=$2m$

Curved Surface Area$=2\pi rh$

$=2\times \frac{22}{7}\times 0.35\times 2$

$=44m^2$

Area covered in 50 rounds= $50\times CSA$

=$50\times 44=2200m^2$