1 Theorem 6.1 - If two lines intersect each other .jpg

2 Theorem 6.1 - Vertically Opposite Angles are equal.jpg

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  1. Chapter 6 Class 9 Lines and Angles
  2. Serial order wise


Theorem 6.1 :- If two lines intersect each other, then the vertically opposite angles are equal. Given :- Two lines AB and CD intersecting at point O. To Prove :- Vertically opposite angles are equal i.e, AOC = BOD and AOD= BOC Proof :- From (1) and (2) AOC + BOC = AOD + AOC BOC = AOD Now, To prove BOD = AOC From (3) and (4) AOD + BOD = AOD + AOC BOD = AOC Hence, Vertically Opposite angles are equal.

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Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 9 years. He provides courses for Maths and Science at Teachoo.