In Δ ABC, AB = AC and the bisectors of ∠B and ∠C meet at a point O. Prove that BO = CO and the ray AO is the bisector of ∠A.
In triangle ABC, we have:
AB = AC (Given)
⇒∠B=∠C
⇒12∠B=12∠C
⇒∠OBC=∠OCB
⇒BO=CO
Now, in △AOB and △AOC, we have: OB=OC (Proved)
AB=AC (Given)
AO=AO (Common)
i.e., ∠BAO=∠CAO (Corresponding angles of congruent triangles)
∴△AOB≅△AOC (SSS criterion)
So, it shows that ray AO is the bisector of ∠A.
Hence, proved.