Question

HELPPPP WITH MATH QUESTION

Answer 1

Answer:I think its the third answer

Answer 2

ANSWER

The correct answer is B.

EXPLANATION

The cosine rule can be used to find the relation for b.

According to the cosine rule:

${b}^{2} = {a}^{2} + {c}^{2} - 2ac \cos( B )$We have that a=4 and c=5 and B=60°

We plug in these values to get:

${b}^{2} = {4}^{2} + {5}^{2} - 2(4)(5) \cos( 60 \degree )$

${b}^{2} = 16+ 25 - 40 ( \frac{1}{2} )$

${b}^{2} = 16+ 25 - 20$

Take positive square root.

$b = \sqrt{25 + 16 - 20}$

The correct answer is B