A circular park is surrounded by a road 21 m wide. If the radius of the park is 105 m, then find the area of the road.
Let r be the radius of the park = 105 m
Given that the circular park is surrounded by a road of width 21 m.
So, Radius of the outer circle = R = (105+21) m = 126 m
Area of the road = Area of the outer circle – Area of the circular park
= πr2 – πR2
= 
= 
= 15246 m2
Hence, the required area of the road is 15246 m2.
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