The Cleaver tool separates both open and closed paths, creating new paths of the same type.
Hold Shift and drag to constrain the angle of the cut line.
See Also
Editing Paths
Straightening Lines
Aligning Points and Segments Horizontally or Vertically
Aligning Points and Segments to an Angle
Spacing Points
Repeating Paths
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 Open Paths
Breaking Paths
Joining Paths
Converting Corners to Right Angle
Removing Tiny Objects