One blade cleans a sector of radius 28 cm and angle 120°: (120/360) x (22/7) x 28² = 2464/3 cm². With two blades, total cleaned area is 2 x (2464/3) = 4928/3 = 1642.67 cm².
A car has two wipers which do not overlap. Each wiper has a blade of length 28 cm and sweeps through an angle of 120°. Find the total area cleaned at each sweep of the blades.
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Given blade length r = 28 cm, angle of sweep θ = 120° and number of wipers = 2.
Area swept by one wiper blade:
Area = (θ / 360) x π x r²
Area = (120 / 360) x (22/7) x 28 x 28
Area = (1/3) x 22 x 4 x 28 = 2464 / 3 cm².
Total area cleaned by both wipers:
Total Area = 2 x (2464 / 3) = 4928 / 3 cm².
In decimal form, 4928 / 3 is approximately 1642.67 cm².
Thus, total area cleaned is 4928/3 cm² (or 1642.67 cm²).
For more NCERT Solutions of Class 9 Ganita Manjari Chapter 6 Measuring Space: Perimeter and Area Question Answer (2026-27)
https://www.tiwariacademy.com/ncert-solutions/class-9/maths/ganita-manjari-chapter-6/