Question

The radii of two circles are 13 cm and 6 cm respectively. The radius of the circle which has circumference equal to sum of the circumference of the two circles is
1. 19 cm
2. 18 cm
3. 16 cm
4. 20 cm

Answer 1

Correct Answer - Option 1 : 19 cm

Given:

The radius of the first circle = 13 cm

The radius of the second circle = 6 cm

Formula used:

Circumference of the circle = 2πr

r = Radius of the circle

Calculation:

Let the radius of the larger circle be R.

The radius of the first circle and the second circle is r₁ and r₂

According to the question,

The circumference of the larger circle = The circumference of the first circle + The circumference of the second circle 

⇒ 2πR = 2πr₁ + 2πr₂

⇒ R = r₁ + r₂

⇒ R = 13 + 6

⇒ R = 19 cm

∴ The radius of the larger circle is 19 cm.