You must use trig for this. If you are using a calculator make use it is first set in degrees!! To find C, you can use cosine, which is adjacent over hypotenuse.
You must use inverse cosine since the sides are given, not the angles.
cos∧-1(120/122)
You have inverse cosine which is cosine negative one and multiply it by adjacent over hypotenuse sides.
The answer is 10.3888 degrees.
