Use this procedure to subtract a selected part from linework, AEC polygons, mass element extrusions, spaces, or from a block containing any of these objects, without having to redraw any of the remaining components. You can also specify the corners of a rectangle as the subtraction. The part to be subtracted can contain or be delineated by lines, polylines (closed or open), arcs, circles, text, or hatches. If the subtraction removes part of a closed polyline, the polyline is recreated as closed. If the subtraction bisects a closed polyline, both parts are recreated as separate closed polylines. However, in cases where the subtraction bisects a hatch, the hatch remains a single linework entity that you can select by clicking either “part.”
Subtracting part of a block with an existing polyline
Subtracting part of a block by specifying rectangle corners