How do you solve a triangle given a = 8, c = 12, and B = 72?
Law of sine and cosine
You first need to fine the missing side, in this case it would be 'b.'
Use this equation:
You will have the side b and can use the the same equation, just manipulated to find the other angle.
That equation is:
That will give you the angle of angle A. Since you have 2 angles of the triangle you can easily find the third, simply subtracting the sum of both angles from 180.