The Modify tools - Introduction to AutoCAD 2011: 2D and 3D Design - page 123

( Fig. 5.43 ), pick Chamfer from the Modify drop-down menu or enter
cha or chamfer at the command line which then shows:

Fig. 5.43 Select Chamfer from the Home/Modify panel

Command:_chamfer
(TRIM mode) Current chamfer Dist1 = 1, Dist2 = 1
Select fi rst line or [Undo/Polyline/Distance/Angle/
Trim/
mEthod/Multiple]: d
Specify fi rst chamfer distance <1>: 10
Specify second chamfer distance <10>: right-click
Select fi rst line or [Undo/Polyline/Distance/Angle/
Trim/mEthod/Multiple]:pick the fi rst line for the
chamfer
Select second line or shift-select to apply
corner: pick
Command:

The result is shown in Fig. 5.44. The other two rectangles are chamfered in
a similar manner except that the No trim prompt is brought into operation
with the bottom left-hand example.

Original
rectangle
100x60

Dist1=10
Dist2=10

Dist1=20
Dist2=20
No trim

Dist1=10
Dist2=15

Fig. 5.44 Examples - Chamfer