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

Given:-

Each wiper has a blade of length 25 cm sweeping through an angle of 115°.

To Find:-

The total area cleaned at each sweep of the blades.

Solution:-

$⟹\textsf{Total area cleaned by 2 wipers = 2 x area cleaned} \\ ⟹\textsf{2 area of sector with 115°}\\ ⟹\textsf{ 2 x 360° = 2} θ \textsf{ x }\pi \textsf{r 2}\\ ⟹\textsf{2 x 360° 115° x 722 x 250} \\ \textsf{Therefore area cleaned by wipers = } \frac{158125}{126} \: \textsf{cm2 } \\\textsf{= 1254.96}$

Answer 2

Given:-

Each wiper has a blade of length 25 cm sweeping through an angle of 115°.

To Find:-

The total area cleaned at each sweep of the blades.

Solution:-

$⟹\textsf{Total area cleaned by 2 wipers = 2 x area cleaned} \\ ⟹\textsf{2 area of sector with 115°}\\ ⟹\textsf{ 2 x 360° = 2} θ \textsf{ x }\pi \textsf{r 2}\\ ⟹\textsf{2 x 360° 115° x 722 x 250} \\ \textsf{Therefore area cleaned by wipers = } \frac{158125}{126} \: \textsf{cm2 } \\\textsf{= 1254.96} \:$