Question

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.
​

Answer 1

Solution :-

Radius of first circle = 19cm

Radius of Second circle = 9cm

Let the radius of the required circle or you can say third circle be r

Circumference of First circle = 2πr

= 2 * π * 19

= 38π

Circumference of second circle = 2πr

= 2 * π * 9

= 18π

Circumference of third circle = 2πr

Given that,

Circumference of 3rd circle = Circumference of 1st circle + Circumference of 2nd circle

2πr = 38π + 18π

2πr = 58π

r = 58π/ 2π

r = 28

Radius of the required circle is 28cm

Answer 2

Answer:

Let the radius of required circle =r cm

Radius of 1st circle r1 =9 cm

Radius of 2nd circle r2 =19 cm

As per the question

Circumference of the required circle = Sum of circumference of two circles

Circumference of small circle =2πr1

=2π×9

=18π

Circumference of small circle =2πr2

=2π×19

=38π

Now,

Circumference of the required circle = Sum of circumference of two circles

2πr=18π+38π

2πr=58π

r= 2π /56π

r=28 cm

Hence, radius of new circle is 28 cm.

Please mark me the brainliest and Rate me and give me thanks.