In ΔABC, AB and AC are produced to points D and E, respectively. If the bisectors of ∠CBD and ∠BCE meet at point O such that ∠BOC=76
∘
, then ∠A= ?
- A56
∘ - B14
∘ - C28
∘ - D76
∘
Solution & Step-by-step Explanation
The point O is the ex-centre of the triangle formed by external angle bisectors.
The relationship between ∠BOC and ∠A is given by:
∠BOC=90
∘
−
2
∠A
Given ∠BOC=76
∘
:
76
∘
=90
∘
−
2
∠A
2
∠A
=90
∘
−76
∘
2
∠A
=14
∘
∠A=28
∘
The relationship between ∠BOC and ∠A is given by:
∠BOC=90
∘
−
2
∠A
Given ∠BOC=76
∘
:
76
∘
=90
∘
−
2
∠A
2
∠A
=90
∘
−76
∘
2
∠A
=14
∘
∠A=28
∘