1. First open the CAD and then in the tool commonly used in the "Modify" toolbar "round Corner" as shown below, you can also use the command.
2.AutoCAD Command prompt:
Fillet Select the first object or [Discard (U) multiple segment (P) radius (r) Trim (T) multiple (M)]: (select radius (r) At this prompt or enter R on the command line and press SPACEBAR.
3. Fillet Specify Fillet radius <0.0000>: (Specify fillet radius) such as enter fillet radius 100, then press SPACEBAR.
4.FILLET Select First object or discard (U) multi-segment (P) radius (R) trim (T) Multiple (M): (select First object in drawing window)
5..FILLET Select the second object, or hold down the SHIFT key to select the object to apply the corner point or radius (R): (Select the second object in the drawing window)
All right, well, that's a pretty good chamfer shape out there, everybody. There are many other graphic buttons in the tool besides this chamfer shape that you can use directly.