TABLE OF CONTENTS Autocad uses the Cartesian Coordinate System.
The Cartesian Coordinate System has 3 axes, X, Y and Z.
The X is the Horizontal axis. ( Right and Left)
The Y is the Vertical axis. ( Up and Down)
The Z is Perpendicular to the X and Y plane.
(The Z axis, which is not discussed in this book, is used for 3D.)
Look at the User Coordinate System (UCS) icon in the lower left corner of your screen. The arrows are pointing in the positive direction.
The location where the X , Y and Z axes intersect is called the ORIGIN. (0,0,0)
Currently the Origin is located in the lower left corner of the screen.
When you move the cursor away from the Origin, in the direction of the arrows, the X and Y coordinates are positive.
When you move the cursor in the opposite direction, the X and Y coordinates are negative.
Using this system, every point on the screen can be specified using positive and negative X and Y coordinates.
There are 3 types of Coordinate input, Absolute, Relative and Polar.
Absolute coordinates come from the ORIGIN and are typed as follows: 8, 5 . The first number (8) represents the X-axis (horizontal) distance from the Origin and the second number (5) represents the Y-axis (vertical) distance from the Origin. The two numbers must...
