As your drawings become more complex, you can rename named objects to keep the names meaningful or to avoid conflicts with names in drawings you insert into the main drawing. You can rename any named object except those that AutoCAD names by default, for example, layer 0.
You can define a hatch boundary by specifying points directly. For example, you may want to illustrate a pattern fill in a small section of a drawing, as shown in the following illustration.
Regions are 2D enclosed areas you create from closed shapes called loops. A loop is a curve or a sequence of connected curves that defines an area on a plane with a boundary that does not intersect itself. Loops can be combinations of lines, polylines, circles, arcs, ellipses, elliptical arcs, splines, 3D faces, traces, and [...]
You erase freehand lines by using the Erase option of the SKETCH command. In Erase mode, wherever the cursor intersects the freehand line, everything from the intersection to the end of the line is erased.
Once you record freehand lines, you can’t edit them or erase them with the Erase option of SKETCH. Use the ERASE [...]
Use inscribed polygons when you want to specify the distance between the center of the polygon and each vertex. This distance is the radius of the circle within which the polygon is inscribed. In this example, you draw an inscribed square, the default polygon.