What is an exterior angle of a triangle? Illustrate using diagram.

Asked by Topperlearning User | 17th Nov, 2013, 11:06: PM

Expert Answer:

When any side of a triangle is produced, the angle so formed, outside the triangle and its vertex, is called its exterior angle.

For example, ACD is an exterior angle as the side BC of ABC is extended. 

 

Clearly, the exterior angle ACD and the adjacent interior angle ACB are supplementary.

i.e.  ∠ACD + ACB = 180o

Answered by  | 18th Nov, 2013, 01:06: AM