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The Radii of Two Circles Are 25 Cm and 18 Cm. Find the Radius of the Circle Which Has a Circumference Equal to the Sum of Circumferences of These Two Circles - Mathematics

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प्रश्न

The radii of two circles are 25 cm and 18 cm. Find the radius of the circle which has a circumference equal to the sum of circumferences of these two circles. 

बेरीज

उत्तर

Circumference of the first circle

S1 = 2π x 25
     = 50π cm

Circumference of the second circle

S2 = 2π x 18
     = 36π cm

Let r be the radius of the resulting circle.
2πr = 50π + 36π
2πr = 86π

r = `(86π)/(2π)`
  = 43 cm

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पाठ 20: Area and Perimeter of Plane Figures - Exercise 20 (C) [पृष्ठ २६१]

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सेलिना Concise Mathematics [English] Class 9 ICSE
पाठ 20 Area and Perimeter of Plane Figures
Exercise 20 (C) | Q 4 | पृष्ठ २६१

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