Last updated at Nov. 23, 2017 by Teachoo
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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AAS and ASA are same
In an isosceles triangle ABC with AB=AC,D and are points on BC such thatBE=CD. show that AD = AE