How to use the command LINE in AutoCAD?
It’s so easy. 2 ways to do that:
1st way:
- Type 
LINE(or justL) in the Command Line. - Press 
Enter. - Click anywhere in the drawing area to specify the first point.
 - Move your cursor and click again to specify the next point.
 - Continue clicking for more line segments if needed.
 - Press 
EnterorEscto end the line command. 
2nd way:
If you know the exact coordinates:
- Type 
L→Enter. - Enter the first point, e.g. 
0,0. - Enter the next point, e.g. 
100,0.
→ This draws a line 100 units long horizontally. - Press 
Enterto finish. 
TIPS:
- Ortho Mode (F8) keeps lines perfectly horizontal or vertical.
 - Polar Tracking (F10) helps you lock to specific angles.