The radii of two circles are 19cm and 9cm respectively has a circumference equal to the sum of the circumferences of the two circles.
1 Answer
Solution:
Given,
The radius of the 1st circle = 19 cm
∴ Circumference of the 1st circle = 2𝜋 x 19 = 38𝜋 cm
The radius of the 2nd circle = 9 cm
∴ Circumference of the 2nd circle = 2𝜋 x 9 = 18𝜋 cm
So,
The sum of the circumference of two circles = 38𝜋 + 18𝜋 = 56𝜋 cm
Now, let the radius of the 3rd circle = R
∴ The circumference of the 3rd circle = 2𝜋R
It is given that sum of the circumference of two circles = circumference of the 3rd circle
Hence, 56𝜋 = 2𝜋R
Or, R = 28cm.
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