What is the value of c2 in the given figure, where the radius of the circle is ‘a’ unit.
Explanation:
By the cosine rule, in a ΔABC with ∠ACB = θ and AB = c, BC = a and AC = b,
cos θ = a2+b2-c22ab
∴ 2 ab cos θ = a2 + b2 – c2
∴ c2 = a2 + b2 - 2ab cos θ
Hence, option (a).
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