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,

Radius (r) = 25 cm

Sector angle (θ) = 115°

• Since there are two blades,

The total area of the sector made by wiper,

$= 2 \times ( \frac{θ}{360} ) \times \pi {r}^{2}$

$= 2 \times ( \frac{115}{360} ) \times ( \frac{22}{7} ) \times {25}^{2}$

$= 2 \times \frac{158125}{252} \: \: {cm}^{2}$

$= \frac{158125}{126} \: \: {cm}^{2}$

$= 1254.96 \: \: {cm}^{2}$

Answer 2

Answer:

Total area cleaned by 2 wipers

=2× area cleaned by 1 wiper

=2× area of sector with 115

∘

=2×

360

∘

θ

×πr

2

=2×

360

∘

115

∘

×

7

22

×25

2

Therefore area cleaned by wipers =

126

158125

cm

2

=1254.96