You are given triangle ABC with angle A=33 degrees, a=6 and c=7. Use law of cosines to show to possible answers for b. How do I solve?

Answer 1

a² = b² + c² - 2bccosA

So, 36 = b² + 49 - 14bcos33°

b² - 11.74b + 13 = 0

Now, use the quadratic formula to solve for b.