I need help on trigonometry

Question

In ?ABC, m∠A=15°, a=9, and b=10. Find c to the nearest tenth.

Answer 1

I see that you've submitted 4 trig problems. Have you begun any of them by making a sketch reflecting the situation?

 

If you do so, you'll have a triangle--label as many angles and sides with the stated measurements.

 

The key will be to see how to solve for various missing parts, using either the Law of Sines or the Law of Cosines.

 

Refer to similar examples in your class material.