How to use Line Commands for AutoCAD . Read for learn this post ;
Summary
List of Prompts :The following prompts are displayed. Specify first point / next point Specify points to draw line segments.Continue :Continues a line from the endpoint of the most recently drawn line.
If the most recently drawn object is an arc, its endpoint defines the starting point of the line, and the line is drawn tangent to the arc.
Close :Ends the last line segment at the beginning of the first line segment, which forms a closed loop of line segments. You can use Close after you have drawn a series of two or more segments.
Undo :Erases the most recent segment of a line sequence.Entering u more than once backtracks through line segments in the order you created them.
