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If (a+b+c) (b+c-a) = 3bc then find angle...

If (a+b+c) (b+c-a) = 3bc then find angle A .

A

`60 ^(@)` 0

B

` 30 ^(@) `

C

` 90 ^(@) `

D

` 45^(@) `

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The correct Answer is:
A
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