- Extends the segment by a
distance to be
constructed.

- Extends the segment to the projection of a
point to be constructed.

- Extends the segment to the intersection with a
line or a
circle to be constructed.
In case of multiple intersection points the segment is extended to
the nearest intersection point. To extend to a specific point the
command must be issued multiple times.

This command can only be used to extend segments. To trim segments see here.