Check sibling questions

Let us consider a triangle ∆ ABC

 

Let ∠ 1 be the exterior angle

 

Since BAD is a line

  ∠ A + ∠1 = 180°      (Linear Pair)

  ∠ 1 = 180° − ∠ A

 

So, in a polygon

  Interior angle + Exterior angle = 180°

  1. Chapter 3 Class 8 Understanding Quadrilaterals
  2. Concept wise

About the Author

Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science and Computer Science at Teachoo