Question

find the size of angle BAC with reasons
O marks the centre of the circle.
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Answer 1

Answer:

∠BOC=2∠BAC, the angle formed at the centre is twice the angle formed at the circumference.

Therefore, ∠BOC=2n

∠OCB=m

Since, OB = OC = radius of the circle = m

Thus, in Δ OBC,

∠OCB+∠OBC+∠BOC=180

∘

2m+2n=180

⇒m+n=90