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In a triangle ABC, if (1 + a/b + c/b)(1 + b/c - a/c) = 3, then the angle A is equal to

(a)  π/3

(b)  π/4

(C)  π/6

(D) None of these

1 Answer

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Best answer

Correct option (a)  π/3

Use cos A.

(b + a + c)(b + c – a) = 3bc

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