Question

If radius of circumcircle of equilateral triangle is 10 units, what is the radius of incircle of the given triangle? 
1. 5 units
2. 7 units
3. 10 units
4. None of the above

Answer 1

Correct Answer - Option 1 : 5 units

Given:

The radius of the circumcircle of an equilateral triangle = 10 units.

Concepts used:

In an equilateral triangle,

The radius of circumcircle = 2 × radius of the incircle

Calculation:

The radius of circumcircle = 2 × radius of the incircle

⇒ 10 units = 2 × radii of incircle

⇒ Radius of incircle = 10/2 = 5 units.

∴ The radius of incircle is 5 units.