0.5722 = Cos C,
Well, once you have the cosine of an angle, then you can find the angle by using "Inverse cosine", and that will give you the angle that you want. So, in this case we have the cosine of C=.5722=55.10 Degrees. You have to use calculator to do that. Inverse cosine is sometimes called "arc-cosine."" Sometimes it's written Cos^-1.
