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23/06/2021 10:48 am
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The radii of two circles are 19 cm and 9 cm respectively. Find the radius of the circle which has a circumference equal to the sum of the circumferences of the two circles.
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23/06/2021 10:49 am
The radius of the 1st circle = 19 cm (given)
∴ Circumference of the 1st circle = 2π×19 = 38π cm
The radius of the 2nd circle = 9 cm (given)
∴ Circumference of the 2nd circle = 2π×9
= 18π cm
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
56π = 2πR
R = 28 cm.