Q5 of 31 Page 183

The radius of a circular park is 3.5 m. A 1.4 m wide footpath is made all round the circular park. Find the area of the footpath.


Given: Radius of the smaller circle AB = 3.5 m


Also, CD = 1.4 m


⇒ Radius of the larger circle AC = AD + CD = 3.5 + 1.4 = 4.9 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


⇒ Area of the path


⇒ Area of the path


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


⇒ Area of the path


⇒ Area of the path


⇒ Area of the path = 36.96 m2


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