PREFACE WHAT IS AUTOCAD? AutoCAD is a PC-based drafting and design software package developed and marketed by Autodesk ® , Inc. As of 2010, it has been around for approximately 28 years--several lifetimes in the software industry. It has grown from modest beginnings to an industry standard, often imitated, sometimes exceeded, but never equaled. The basic premise is simple and one of the reasons for AutoCAD's success. Anything you can think of, you can draw quickly and easily. For many years it helped if this "anything" was 2D in nature, as AutoCAD is essentially a superb electronic 2D drafting board. In recent releases, however, its 3D capabilities finally matured, and AutoCAD is now also considered an excellent 3D visualization tool. The software has a rather steep learning curve to become an expert but a surprisingly easy one to just get started. Most important, it is well worth learning. This is truly global software that has been adopted by millions of architects, designers, and engineers worldwide. Over the years Autodesk has expanded that reach by introducing add-on packages that customize AutoCAD for industry-specific tasks, such as electrical, civil, and mechanical engineering. However,