How to write the angle format (º ‘ ‘’) on the cell?

1. How to show the angle format in the cell, for example I need to type an angle like 120º12’23’’

2. How to do the calculation, for example 120º12’23’’ + 15º20’30’’

3. How to write “if statement” for example:

If c2>180º, then b2+15º20’30’’

If c2<180º, then b2-15º20’30’’

Thank you for the help

Best

Jamal