How to enter 2D Coordinates?

[pferreira]

There are 2 major ways to locate points when creating objects, by entering Cartesian Coordinates and by entering Polar coordinates
In the Cartesian coordinates we can use absolute or relative Cartesian coordinates to locate points, to use the Cartesian coordinates we enter a x and a y value separated by a comma (x,y), Absolute coordinates are used when we no where in the drawing is the precise x and y values of a point. for example :
Command: line
Specify first point: 1,1
Specify next point or [Undo]: 2,3

Relative coordinates are based on the last point entered, for example we have a point at absolute coordinates 2,2 and want another point 2 units along the x axis and 3 units along y axis (it gives the absolute coordinate at (4,5)) from the last point (2,2), we can precede the new coordinate value with an @ sign.
example:
Command: line
Specify first point: 2,2
Specify next point or [Undo]: @2,3

Absolute or relative polar coordinates works with distance and angle to locate points, we use polar coordinates by entering a distance and an angle separated by an angle bracket (<).
Absolute polar coordinates are measured from the UCS origin (0,0) and angles increase in the counterclockwise direction by default.
example:
Command: line
Specify first point: 0,0
Specify next point or [Undo]: 2<45
Specify next point or [Undo]: 3<90
In this example two lines are created, one uses the Absolute Cartesian points 0,0 and 1.41,1.41 and the other uses 1.41,1.41 and 0,3.

Relative coordinates are based on the last entered point, you just need to use the @ sign.
example:
Command: line
Specify first point: 0,0
Specify next point or [Undo]: @2<45
Specify next point or [Undo]: @3<90
In this example two lines are created, one uses the Absolute Cartesian points 0,0 and 1.41,1.41 and the other uses 1.41,1.41 and 1.41,4.41

Best Regards

[Chris Matira]

this looks more like a basic cad tutorial than a tip/trick... =)

[Wanderer]

this looks more like a basic cad tutorial than a tip/trick... =) sounds like the same thing to me. ;) experience levels vary widely.

[robert.1.hall72202]

This could be useful information for a new trainee. Thanks for typing this out.
I could use this post for something.

[jpaulsen]

With the introduction of Dynamic Input in AutoCAD 2006 you have the option to set coordinate entry to absolute or relative. The default setting is relative, which behaves differently then previous versions. You need to use a # symbol to input absolute coordinates.

Absolute coordinates are measured from the UCS origin (0,0).
example:
Command: line
Specify first point: 0,0
Specify next point or [Undo]: #2,2
In this example a line is drawn from the Absolute Cartesian points 0,0 to 2,2.

Command: line
Specify first point: 10,10
Specify next point or [Undo]: 2,2
In this example a line is drawn from the Absolute Cartesian point 0,0 to 12,12. Since relative coordinate entry is the default, the @ symbol is not necessary.