Closing and joining magenta lines

as requested on support…

Given regions which are not closed and which one wishes to be closed:

There are several different ways to close the regions, depending on the desired effect.

One approach is to select the geometries which make up to edges which one wishes to add to the open geometry:

copy then, then with the cursor outside the drawing area, paste them in place:

Then, draw in geometry which defines the portions of these geometries which need to be added to the open geometry to create a closed region:

Using the Polyline tool is easiest:

Done

Add the elements to the selection by shift-clicking:

and then use the Trim Vectors tool to remove what is not wanted:

If necessary, pan around and zoom in/out:

until one arrives at:

OK

Then select the geometry for each region which one wishes to close:

and use Join Vectors:

Yes

Clean up by removing the unneeded lines: