AUTOCAD IMPORTANT USEABLE COMMANDS :
1. L+ENTER=LINE.
2. CO+ENTER=COPY.
3. C+ENTER=CIRCLE.
4. REC+ENTER=RECTANGLE.
5. OF+ENTER*2=OFFSET.
6. E+ENTER=ERASE/DELETE.
7. TR+ENTER*2=TRIM
8. DLI+ENTER=DIMENSION
9. DAL+ENTER=DIAGONAL DIMENSION
10. UN=UNIT FOR DIMENSION
11. D=DIMENSION CHANGES
12. LINE=LINE
13. CIRCLE=CIRCLE=CIRCLE OF 1P,2P & 3P
14. TRIM=TRIM ENTITIES