The coordinate axes show the location of the origin and direction of the positive x-axis of the coordinate system. The origin is at the intersection of the axes and the positive x-axis is indicated by a tick mark near the origin. The positive y-axis is always 90 degrees counter-clockwise from the positive x-axis.
Since the axes is a track, it has a track menu that is accessible in the Tracks menu on the menu bar or by right-clicking the main video view.
Display the axes by clicking the axes button 
on the toolbar.
Select and drag or nudge the origin to a desired location in the main video view.
Select and drag or nudge the positive x-axis to rotate the axes about the origin. Hold down the shift key to restrict angles to 5 degree increments.
The angle is displayed in the angle field on the toolbar. A desired angle may be entered directly in this field.
Locking the axes prevents it from making any changes to the origin or angle. Lock the axes by turning on the Locked property in its track menu.