Unit of measurement used to express the value of an Angle.
| Degree | Interprets an angle as degrees. | 
| Gradian | Interprets the measurement of an angle in gradians. One full circle is 400 gradians | 
| Radian | Interprets the measurement of an angle in radians. One full circle is 2Pi radians which approximates to 6.2832 radians | 
| Turn | Interprets the measurement of an angle, expressed as a number of turns. One full circle is one turn. |