Filleting an Entire Polyline in AutoCAD

You can fillet an entire polyline or remove fillets from a polyline. The polyline can contain arc segments, which have the same fillet radius as line segments in the polyline.
If you set a nonzero fillet radius, AutoCAD inserts fillet arcs at each vertex where two line segments meet if the segments are long enough to accommodate the fillet radius.

To fillet an entire polyline

1. From the Modify menu, choose Fillet.
2. Enter p (Polyline).
3. Select the polyline.

If two polyline line segments are separated by one arc segment and the two line segments converge as they approach the arc segment, AutoCAD removes the arc segment and replaces it with a fillet arc.

If you set the fillet radius to 0, no fillet arcs are inserted. If two polyline line segments are separated by one arc segment, AutoCAD removes that arc and extends the lines until they intersect.

This method provides a quick way to join two endpoints. However, if the lines do not converge as they approach the arc segment, no change occurs.