Question

A car has two wipers which do not overlap. Each wiper has a blade of length 25 cm sweeping through an angle of 115°. Find the total area cleaned at each sweep of the blades.

Answer 1

It can be observed from the figure that each blade of wiper will sweep an area of a sector of 115° in a circle of 25 cm radius.

Area of such sector = $\frac{115° }{ 360°} \times \pi \times (25)^2$

= $\frac{23}{ 72} \times \frac{22} 7 \times 25 \times 25$

= $\frac{158125 }{ 252}\, cm^2$

Area swept by 2 blades = $2 \times \frac{158125}{ 252}$ = $\frac{158125} { 126}\, cm^2$