Meshes and Surfaces - Autodesk AutoCAD 2013 Practical 3D Drafting and Design - page 408

really intersect. The PROjection direction defines how trimming geometry is projec-
ted onto surfaces to trim, may be Automatic , View , UCS , or None :
Select surfaces or regions to trim or [Extend/
PROjection direction]: Selection
Select surfaces or regions to trim or [Extend/
PROjection direction]: Enter
The command prompts for objects (surfaces, regions, or linear objects) that define
trimming boundaries:
Select cutting curves, surfaces or regions:
Selection
Select cutting curves, surfaces or regions:
Enter
We specify a point on the area or side to be trimmed. The prompt is repeated until
the Enter key is pressed. The Undo option undoes last trim:
Select area to trim [Undo]: Point
Select area to trim [Undo]: Enter