On the dialog, select Angle Option > Perpendicular to create a plane perpendicular to the
selected face. Select Angle Option > Parallel to create a plane parallel to the selected face.
This method creates a plane, which lies at the midway between two selected faces. Activate
the Datum Plane command and select Type > Bisector on the Datum Plane dialog. Click
on two faces of the model geometry. Click OK to create the bisector plane.
Curves and Points
This method creates a datum plane passing through three points. Activate the Datum Plane
and select Type > Curves and Points on the Datum Plane dialog. Select three points from
the model geometry. A plane will be placed passing through these points.