AutoCAD Reference 2007 - 2010 on Windows Pc

AutoCAD Reference 2007 - 2010 AutoCAD is a high end CAD (Computer Aided Drafting) Program. It has a multitude of features which this book will try to address.

AutoCAD is a vector based drawing application intended for engineering purposes. Commands can be entered at a command line or through toolbars and menus. DWG Files

AutoCAD drawings are saved using the DWG extension, and over the years this has become a standard format for exchanging technical drawings, to the extent that even programs such as Adobe Illustrator will recognise DWG files. AutoCAD also supports an even more widely recognised format called DXF which was specifically designed as an interchange format. Unfortunately, as AutoCAD has passed through numerous editions, the DWG format has upgraded to keep pace with newer features. The most recent format was released with AutoCAD 2012 and any files saved using this format cannot be opened by AutoCAD 2011, 2010, 2009 etc.
Basic drawing tools
Point

Creates a symbol on the drawing that is tied to a specific point. It is defined by coordinates (x,y,z). It is not necessary to create points when you want to draw other geometric entities.
Construction line tools

Ray = A line with a defined starting point with infinite length at a specified slope, the command for which is "RAY" and then you need to give the specifications.

Xline = An infinite line with no start or end point at a specified slope. Base point can be snapped with middle point snap mode. Shortcut "xl"
Polyline

Polylines are the main business of most drawings. A polyline is made of numerous lines/arcs/or both segmented together into one selectable object. Polylines are quite versatile and the PEDIT(Polyline Edit) command can be used to access & edit many of the features associated with them. Shortcut "pl"
Polygon

Polygons are regular, multisided shapes such as pentagons, hexagons etc. When this tool is employed, AutoCAD requests the number of sides desired and then asks whether the shape is to be defined as sitting on a circle of specified radius, or by the length of a side. The objects created from this command become "Closed Polylines" and can be edited using PEDIT.
Rectangle

This is a quick way of drawing a four-segment polyline with four right angles. Shortcut "rec".
Arc

An arc is a circle segment. When using this tool the user can define the arc by selecting three points through which AutoCAD will generate an arc, or alternatively the user can define a center point, a radius and a range of degrees to fill.
Circle

The only variables here are radius and centre point. Shortcut "c"
Spline

Splines are a particular form of curve generated by specific mathematical equations. The user can select as many vertices as they wish, and AutoCAD will generate a spline curve that incorporates all these points. Splines are generally used for cosmetic purposes, as their mathematical complexity makes them hard to define from a technical design perspective. Shortcut "spl"
Ellipse

Basically an oval. Similar to a circle, except ellipses require a radius to be defined for both their vertical and horizontal components. Shortcut "el"
Hatch

Hatches are area fills. They can be made up of a solid color, a gradient (in later versions of AutoCAD) or more usually a specific pattern. Hatches can be applied to a particular object such as a looped polyline, or any enclosed area. They can be (and usually should be) defined as being "associative" which means that if the area in which they are contained is adjusted, the hatching will update automatically.
Text
Inserts a text string into the drawing. AutoCAD uses two forms of text entry, single line and multiline. These are known respectively as DTEXT and MTEXT. DTEXT is very much a leftover from AutoCAD's early years and there is no real justification for using its very basic system when the MTEXT option has features similar to a conventional text editor.you may also select command TEXT for undefined area.

This is Reference manual app please note

Allows applications to open network sockets.
Allows applications to access information about networks.
Allows applications to access information about Wi-Fi networks.
Allows an application to write to external storage.
Allows an application to read from external storage.