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### 18-3. 2D Coordinates - RELATIVE recentangular

In the picture above you see what it looks like the drawing coordinate system with relatively coordinates.

Relative rectangular coordinates are points that are located at some distance from the origin to a point where we are now and make the intersection of axes X and Y.
UCS us can be located anywhere in this case the drawing using the relative coordinates of all because it is important to point at where you currently are.

When working with relative coordinates is an important initial quadrant for the current point (the intersection of the coordinates) which is currently located and it is a starting point from which we start. Quadrant look in relation to the point where we are.

Given that relatively coordinate system based on the X, Y coordinates from the starting point of the current point in which we find ourselves so we take this opportunity to work the system to use the X and Y coordinates for a set of points on the desktop.

IMPORTANT! Remember that in dealing with relative coordinates are always moving from the point at which you are, wherever he was placed on the UCS diagram (desktop). So we always X = 0 and y = 0 as a starting point.

While entering the coordinates of the first to enter the coordinates X and Y coordinates and then, they are separated by a comma.

Before drawing must run the command that we want to draw a line or polyline, etc. .. and then determine the coordinates of which are the intersection of X and Y axis but inscribed with the @ sign (ET) in front of the coordinates.
This character type key combination (AltGr + V or Alt +64 on the numeric keypad). example: (@ 50,35)

EXAMPLE 1
See an example of the relative coordinates. An important @ sign, because it determines that the starting point where we are.

Command: LINE
Specify first point: 10,10 [set the starting point of using the absolute coordinate system]
Specify next point or [Undo]: @ 10,0 [is at point 1, in paragraph 1, type @, and coordinates with AutoCAD our position in the point 2]
Specify next point or [Undo]: @ 0,5 [found in article 2, paragraph 2 Enter the coordinates with @ and AutoCAD positioned us to point 3]
Specify next point or [Close / Undo]: @ -5,5 [found in article 3, paragraph 3, type in the coordinates with @ and AutoCAD our position in point 4]
Specify next point or [Close / Undo]: @ -5,0 [is at point 4, in paragraph 4 Enter coordinates with @ and AutoCAD our position in the point 5]
Specify next point or [Close / Undo]: @ 0, -10 [found in article 5, paragraph 5 Enter the coordinates with @ and AutoCAD our position in point 6, ie point 1]
Specify next point or [Close / Undo]: ESCAPE (ESC) completion of drawing

This example above we can draw with the mouse using the Ortho-mode but with the additional entry of line length.

- switched function button for ORTHO mode
- Running the Line
- determining the starting point of 10,10 [Item 1]
- is at point 1, the mouse EAST determine the direction and then in the command line prompt by entering 10 [item 2]
- Located in section 2, determine the direction of the mouse and then NORTH command line prompt by entering 5 [item 3]
- is at point 3 (ORTHO mode does not allow drawing diagonal lines (although we can click somewhere diagonally), so we use the relative coordinates, the starting point for us is now at point 3, as we enter relative coordinates), type the command line prompt relative coordinate @ - 5,5
- is at point 4, the mouse determine the direction of WEST and then type 5 [item 5]
- is at point 5, the mouse determine the direction of South and then type 10 [item 6]

EXAMPLE 2
We are at a point on the desktop and not know that we are the coordinates of that point. It does not matter. Using relative coordinates, we can draw a line with no problem as we want.

Command:
Command: _line Specify first point: [the first point we have determined the click of the mouse]
Specify next point or [Undo]: @ 7,7 [X = 7, Y = 7 means that we have the X and Y switch 7 units from the starting point for which we do not know the coordinates unless position ourselves at the point and the status of the View toolbar are the coordinates. ]