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Question
The radii of two circles are 48 cm and 13 cm. Find the area of the circle which has its circumference equal to the difference of the circumferences of the given two circles.
Solution
Circumference of the first circle
s1 = 2π x 48
= 96πcm
Circumference of the first circle
s2 = 2π x 13
= 26πcm
Let r be the radius of the resulting circle.
2πr = 96π - 26π
2πr = 70π
r = `(70π)/(2π)`
= 35cm
Hence area of the circle
A = πr2
= π x 352
= 3850cm2
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