In a A B C, if c ^2+ a ^2- b ^2= ac, then B = - Vidyadip

MCQ

In a $\triangle A B C$, if $c ^2+ a ^2- b ^2= ac$, then $\angle B =$

A
$\frac{\pi}{6}$
B
$\frac{\pi}{4}$
✓
$\frac{\pi}{3}$
D
None of these

✓

Answer

Correct option: C.

$\frac{\pi}{3}$

(C) $\cos B =\frac{ c ^2+ a ^2- b ^2}{2 ac } \Rightarrow \cos B =\frac{1}{2} \Rightarrow B=\frac{\pi}{3}$

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