Q8 of 31 Page 178

The radius of a circular grass field is 35 m. There is a 7 m wide path all around it. Find the area of the path.


Given: Radius of the smaller circle AB = 35 m


Also, CD = 7 m


⇒ Radius of the larger circle AC = AD + CD = 35 + 7 = 42 m


Area of the path = Area of the larger circle – area of the smaller circle


∵The area of a circle = πr2


⇒ Area of the path = πR2 - πr2




Using (a+b)(a-b) = a2 - b2




⇒ Area of the path = 22× 77 = 1694 m2


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