Question

The diameters of two circles are 56 cm and
28 cm, respectively. Find the radius of the circle
which has circumference equal to the sum of
the circumferences of the two circles.​

Answer 1

Circumference of first circle ⭕️
diameter = 56cm
radius = 56 divided by 2 = 28cm
Circumference = 2 pie r
= 2 x 22/7 x 28 = 176 cm
Now,
Circumference of second circle ⭕️
Diameter= 28cm
Radius = 28 divided by 2 = 14cm
Circumference = 2 pie r
= 2 x 22/7 x 14 = 88cm
Now the sum of circumference of both circles is equal to the circumference of the third circle ⭕️.
So,
Circumference of the third circle = 176+88
= 264 cm
Now we have to find the radius of the third circle .
Circumference = 2 pie r
264 = 2 x 22/7 x r

264 x 7
———— = r
22 x 2

42 cm = r
Therefore the radius of the third circle is 42cm.