Moving a line segment

You can move a line segment by clicking it on its middle point and dragging it left-right (vertical segments) or up-down (horizontal ones). The cursor will change from the Normal Select to Horizontal/Vertical Resize.

While a segment is being dragged you will see its future shape in the form of a dotted line:

Notice that, in this example, the ending point of the moved line is changing depending on the new position of the segment.

If a straight line is moved then both its end points are changed:

In order to modify a line you have to drop the segment in the selected place.