Select two lines to create an angle dimension between them. By varying the selection order and location, you can control whether you are dimensioning the acute, obtuse, or 360° minus the acute or obtuse angle. The selection process gives you the flexibility to create any kind of angle dimension you may want. Imagine the intersection of the two lines as the center of a clock. Then the end of the lines that you select nearest will be the direction of the hands on the clock. Finally, the dimension will measure the angle counter clockwise from the first selected line to the second. You may then position the text of the dimension where you want it.

The Alternate Angle right mouse button option allows you to switch to any of the four possible angles by repeatedly selecting this option.