You can create several copies of an open path, creating a closed path.
Original path
After Step and Repeat
See Also
Editing Paths
Straightening Lines
Aligning Points and Segments Horizontally or Vertically
Aligning Points and Segments to an Angle
Spacing Points
Acquiring and Applying Length and Angle
Rounding Corners
Sharpening Corners
Converting Segment into a Curve
Converting Segment to Smooth Arc
Converting Segment to 3-Point Arc
Converting Segment to Arc
Eliminating Extra Points
Removing One Point
Adding One Point
Removing Self-Intersections
Changing Starting Point
Separating to Closed Paths
Separating to Open Paths
Breaking Paths
Joining Paths
Converting Corners to Right Angle
Removing Tiny Objects