by John Flanagan
Introduction
A fillet or round connects two objects with a tangent arc in 2D or creates a rounded transition between the adjacent faces of a 3D solid.
An inside corner is called a fillet, and an outside corner is called a round; you can create both using the FILLET command.
Note: The Multiple option can also be used to fillet or round more than one set of objects without exiting the command.
Understand the Trim Mode Options
The no trim mode setting allows placement of the fillet arc without deleting or trimming any of the existing elements.
Trim
Selected objects or line segments are trimmed to meet the endpoints of the fillet.
No Trim
Selected objects or line segments are not trimmed before the fillet is added.
The current value is stored in the TRIMMODE system variable.