
Click Tools > Measure .

On the ribbon, click Measure Angle Between 3 Points.

Place the three points in the model.
The angle between the points appears next to the pointer.

Rightclick to quit the Measure command.

When you measure an angle, the Angle and Apparent angle boxes appear on the ribbon. The Apparent angle box displays the angle of the lines projected onto the active view plane. If lines intersect (coplanar), then both the Angle and Apparent angle boxes display values. If lines do not intersect (are not coplanar), then only the Apparent angle box displays a value.