Question

10. In an isosceles triangle ABC, the bisectors of L B and LC meet at a point O. If
LA= 80° then L BOC is
​

Answer 1

Answer:

Given BD is Bisector of ∠ABC and CO is Bisector of ∠ACB produce CB to D

In ΔABC

AB=AC

∠ACB=∠ABC

2

1

∠ACB=

2

1

∠ABC

∠OCB=∠OBC

in ΔBOC

∠OBC+∠OCB+∠BDC=180

∘

2∠OBC+∠BOC=180

∘

∠ABC+∠BOC=180

∘

∠ABC+∠OBA=180

∘

∠DBA=∠BOC

Answer 2

Step-by-step explanation:

Given BD is Bisector of ∠ABC and CO is Bisector of ∠ACB produce CB to D

In ΔABC

AB=AC

∠ACB=∠ABC

21∠ACB=21∠ABC

∠OCB=∠OBC

in ΔBOC

∠OBC+∠OCB+∠BDC=180∘

2∠OBC+∠BOC=180∘

∠ABC+∠BOC=180∘

∠ABC+∠OBA=180∘

∠DBA=∠BOC