Redraw or extend a selected path segment with the Redraw Path tool
When
you use the Redraw Path tool, the path's stroke, fill, and effect
characteristics are retained.
From the Pen tool pop-up menu, select the Redraw Path
tool
.
(Optional) Change the precision level of the Redraw Path
tool by selecting a number from the pop-up menu in the Precision
box of the Property inspector. The higher the number, the greater
the number of points that appear on the path.
Move the pointer directly over the path.
Drag to redraw or extend a path segment.
Release the mouse button.