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 - Mathematics

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Sum

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.

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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 = πr
   = π x 352
   = 3850cm2  

  Is there an error in this question or solution?
Chapter 20: Area and Perimeter of Plane Figures - Exercise 20 (C) [Page 261]

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Selina Concise Mathematics Class 9 ICSE
Chapter 20 Area and Perimeter of Plane Figures
Exercise 20 (C) | Q 5 | Page 261

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