I have a line digitized in the map display window and I want to add two
segments so it bounds an area. I'll then convert that area to a raster MASK.
Tried using the 'edit line/boundary' feature but it's not adding the
segments to the existing line. Putting the cursor on one end vertex and
issuing a left-click, I drag the line to a corner, left-click, continue
dragging to the second line end vertex, double left-click (which turns the
exiting line from black to dashed yellow), then right-click. The original
line remains.
What have I done incorrectly here?
Rich