Measure > Angle, 3 Points (3D Menu)

This command can be used to measure the angle between two vectors defined by three 3D points in a plane.

Any component corner can be identified as the first point in the plane by clicking near to it.

Any component corner can be identified as the second point in the plane by clicking near to it.

Any component corner can be identified as the third point in the plane by clicking near to it.