To Join Polylines, Splines, Lines, and Arcs Into a Single Polyline

1. Click Modify > object > Edit Polyline. Select a polyline, spline, line, or arc to edit. If you selected a spline, line, or arc, press Enter to convert the selected object into a polyline.
2. Enter j (Join).
3. Select one or more polylines, splines, lines, or arcs that are located end to end.
4. Press Enter to end the command.

Note:

• Spline-fit polylines return to their original shape when joined. Polylines cannot be joined into a Y shape.
• If the properties of several objects being joined into a polyline differ, the resulting polyline inherits the properties of the first object that you selected.