Question

The radii of two circles are 13 cm and 6 cm respectively. Find the radius of the circle which has circumference equal to the sum of circumference of the two circles?
Plz answer in easy language

Answer 1

Answer:

Answer

Given: Radius of 1

st

circle=r

1

=9cm

Radius of 2

nd

circle=r

2

=19cm

Let the radius of required circle=rcm

According to the question,

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

Circumference of small circle=2πr

1

=2π×9=18π

Circumference of larger circle=2πr

2

=2π×19=38π

Now,Circumference of required circle=Sum of circumference of two circles.

2πr=18π+38π

2r=56

r=28cm

Hence radius of new circle =28cm

Answer 2

Answer:

circumference of the circle having radius = 13cm

here r = 13 cm

circumference of circle = 2πr

2π × 13

= 26cm

and other hand

circumference of circle having radius 6cm

here r = 6cm

circumference of circle =2 or

2π × 16 = 12 πcm

sum of the both circumference of circle.

26π + 12 π = 38π cm

let r be the radius of the required circle whose circumference is 38π cm.

[sum of the both circumference of circle.]

next ,

2 πr = 38π

r = 38 / 2

r = 19cm

hence ,.

radius of the new circle is 19 cm.