The Sum of the Circumference and Diameter of a Circle is 116 Cm. Find Its Radius - Mathematics

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Sum

The sum of the circumference and diameter of a circle is 116 cm. Find its radius. 

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Solution

Let r be the radius of the circle.

2πr + 2r = 116

2r( π + 1) = 116

               r = `116 / (2 (π + 1 )`

                  = 14 cm

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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 3 | Page 261

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