Question 1 - Area/Perimeter of Circle - Chapter 11 Class 10 Areas related to Circles

Last updated at August 17, 2026 by

Ex 12.1, 1 - The radii of two circles are 19 cm and 9 cm - Ex 12.1

Ex 12.1, 1 - Chapter 12 Class 10 Areas related to Circles - Part 2

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Question 1 The radii of two circles are 19 cm and 9 cm respectively. Find the radius of the circle which has circumference equal to the sum of the circumferences of the two circles. Given that, Radius of 1st circle = r1 = 9 cm Radius of 2nd circle = r2 = 19 cm Let the radius of required circle = r cm According to question, Circumference of required circle = Sum of circumference of two circles Now, Circumference of required circle = Sum of circumference of two circles 2𝜋r = 18𝜋+38𝜋 2𝜋r = 56 𝜋 r = 56𝜋/2𝜋 r = 28 Hence, radius of new circle = r = 28 cm

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