Introduction to 3D Design - Autodesk AutoCAD 2013 Practical 3D Drafting and Design - page 21

To create regions, we must have their contours already drawn. Contours can be
lines, arcs, circles, ellipses, elliptical arcs, and splines. In 2D, regions are created
with two commands:
• REGION : This command (alias REG ) creates regions from closed objects
or sets of linear objects that define a closed boundary. It only prompts for
the selection of objects and the original objects by default are deleted.
• BOUNDARY : This great command (alias BO ) allows for the easy creation of
closed polylines or regions by specifying internal points to closed bound-
aries. An example follows.
Exercise 1.2
We are going to create some 2D objects and from them, some regions.
1. Start AutoCAD and create some 2D linear objects, similar to those shown
in the following image. For now, dimensions are not important.