Question

43. The diameter of two circles are 36 cm and 20 cm respectively. Find the area of the circ
which has circumference equal to the sum of the circumferences of the two circles. Al
find ratio of area of this big circle and the sum of area of two small circle.
on one circle. I​

Answer 1

Step-by-step explanation:

Given-

The diameter of the two circles are

d

1

=36 cm⇒ radius r1 =

2

d1 =

20

36

cm=18 cm and

d2

=20 cm⇒ radius r

2

=

2

d

2

=

2

20

cm=10 cm.

∴ The circumference C

1

=2πr

1

=2π×18cm=36π cm and

The circumference C

2

=2πr

2

=2π×10 cm=20π cm

So C

1

+C

2

=(36+20)π cm=56π cm.

This is the circumference C of the resulting circle.

∴C=C

1

+C

2

=56π cm

Let the radius of this circle be r.

Now, the radius of a circle =

2π

circumference

∴r=

2π

56π

cm=28 cm.

I HOPE YOU CAN UNDERSTAND