Creating the 3D Geometry

To give the outer profile some depth

1. Click the Edit menu then click Transform ► Project.

2. In the Project dialog click in the Z box and type -20. Click OK.

3. In the top view double-click one of the lines of the outer profile.
   All of the lines in the profile will be displayed in the highlight colour.

4. Right-click to finish the command.
   
   

Note how you can see projected lines appearing in the bottom isometric view.