Editing Solids and Surfaces - Autodesk AutoCAD 2013 Practical 3D Drafting and Design - page 220

The Face option
Upon entering the Face option, we have several additional options. Undo undoes
the last applied option and eXit returns to the previous level. When selecting faces,
Undo and Remove options are available, allowing us to undo the last selection op-
eration or entering the mode to remove faces from the selection:
Enter a face editing option
[Extrude/Move/Rotate/Offset/Taper/Delete/Copy/
coLor/mAterial/Undo/eXit] <eXit>: Option
Note
We must be careful when selecting faces. If we click an edge, both faces sharing
that edge are selected.
The options are as follows:
• Extrude : This option allows you to extrude faces. It prompts for faces se-
lection, the height of extrusion, and the angle of taper for extrusion. A
positive value for height adds volume, while a negative value removes
volume. An angle not equal to zero allows us to taper the new volume.
• Move : This option allows moving of faces. After selection, it prompts for
displacement, for instance, with two points similar to the MOVE command.