Question

The angle between the external bisectors of two angles of a triangle is ${50}^{\circ }$ then the third angle is

• A. ${75}^{\circ }$
• B. ${80}^{\circ }$
• C. ${85}^{\circ }$
• D. ${90}^{\circ }$

Answer 1

The correct option is B ${80}^{\circ }$

Given external bisector of two angle of triangle is ${50}^0$

Then internal angle of triangle is ${50}^0$

Then two angle is ${50}^0$

we know that sum of three angle of triangle is 180

Then third angle of triangle =$180-50-50={80}^0$