Angle

Selection prerequisites: Three points.

Measures the angle defined by the three selected points, using the angle units chosen on the Units panel of the Preferences dialog box. The first selected point defines the initial side of the angle, the second defines the vertex, and the third defines the terminal side of the angle.

When measuring an angle, always select the vertex second.

If angle units in Preferences are set to directed degrees or radians, the value of the measurement can be either positive or negative. A counter-clockwise angle results in a positive measurement, and a clockwise angle results in a negative measurement. Possible values range from –180° to +180°, or from –pi radians to pi radians.

If the angle units are set to degrees, all angle measurements are positive, between 0° and 180°.