Question

5. (1) The radii of two circles are 16 cm and 11 cm respectively. Find the radius of the circle which has circumference equal to the sum of the circumferences of the two circles. (i) 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 circumference s of the two circle​

Answer 1

Answer:

Let the radius of required circle =r cm

Radius of 1st circle r

1

=9 cm

Radius of 2nd circle r

2

=19 cm

As per the question

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

Circumference of small circle =2πr

1

=2π×9

=18π

Circumference of small circle =2πr

2

=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.