Work Planes
In 3D, you can create 3D objects by defining 2D objects in work planes  and then extruding  and revolving these into 3D objects. You can also get a cross section 2D object by intersecting a 3D object with the work plane.
To add a WorkPlane feature, use
model.component(<ctag>).geom(<tag>).create(<ftag>,"WorkPlane");
You access a work planes 2D geometry sequence by the geom() method. To add a 2D feature to a work plane, use
model.component(<ctag>).geom(<tag>).feature(<ftag>).geom().create(<ftag1>,ftype);
where <ftag> refers to a WorkPlane feature and ftype refers to a 2D feature type.
A work plane’s geometry sequence does not contain a Finalize feature.
A work plane’s geometry sequence inherits its settings from its 3D sequence.
For more information on the settings for a geometry sequence see Geometry Settings.
When you build a work plane feature, its corresponding 2D sequence builds automatically and the geometry objects defined by the 2D sequence embed into 3D geometry objects in the 3D sequence. You can then extrude or revolve these embedded point, curve, or surface objects into curve, surface, or solid objects, respectively, using Extrude or Revolve features, respectively.
Methods on model.component(<ctag>).geom(<tag>) can also be used on model.component(<ctag>).geom(<tag>).feature(<wptag>).geom().