If O is the ortho centre of ΔABC and ∠BOC = 100°, the measure of ∠BAC is?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 80°.
O is the orthocentre of ΔABC
And
∠BOC = 100°
In the figure:
∠OPA = ∠OQA = 90°
And
∠BOC = ∠POQ = 100°
In quadrilateral APOQ:
∠APO + ∠POQ + ∠OQA + ∠ QAP = 360°
⇒ 90° + 100° + 90° + ∠QAP = 360°
⇒ ∠QAP = 360° – 280° = 80°