You can use the Set Center Lines function in the Tools menu to create center lines between parallel and non-parallel lines.
Select the lines with the mouse one by one in the work window. As soon as you move the pointer over the second line, you can see the center line in a preview.
If the lines are parallel, the center line is created between the lines and the length is adjusted.
If the line is not parallel, the center line results from the center points between the start and end points of the lines.