In triangle abc, a = 9, c = 5, and b = 120°. find b2.

(D)

Step-by-step explanation:

Given: In triangle ABC, a=9, c=5 and ∠B=120°.

To find: The value of .

solution: It is given that In triangle ABC, a=9, c=5 and ∠B=120°.

Now, using the law of cosines, we get

Substituting the given values, we get

which is the required value of .

Therefore, option D is correct.

2nd one in the first row is correct