>>1655444Since you are most likely in Inkscape, just draw the main shape first, then draw the shape around the area you want to delete. Make sure they are in the same layer, and make sure the shape you wanted to delete is above the other shape, so the green lines should be over the black lines below it. Then Shift+Click both so they are both selected. You should then be able to hit Ctrl+- and it will work.
