When i click the macro then the Line, macro needs to create 2 parallel lines to this line(OFFSET), first one is 4" off on the north side of the selected line and the second one will be 8" off on the north side of the selected line. Then 2 perpendicular lines between offsetted lines end gonna close the shape.
Usage: We are manufacturing countertops. After drawing the countertops adding a 4" strip to the back.