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Question
Find the area enclosed between two concentric circles, If their radii are 6cm and 13cm respectively.
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Solution
We know,
The area of the ring between two concentric circles equals the area of the larger circle minus the area of smaller circle. Let the radius of the outer and inner ring be R and r respectively.
Here, the radius of the outer circle
= 13cm and the radius of the inner circle
= 6cm
The Area of a Circle with radius r = πr2
The area of the ring = π(13)2 - 62)
= `(22)/(7)(169 - 36)`
= `(22)/(7)(133)`
= 22 x 9
= 418cm2.
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