2013

From point: 0,0,5
To point: 3,4
both endpoints of the line will have a Z value of 5. When you begin or open
any drawing, the initial default value of Z is greater than 0.
Use Absolute and Relative Coordinates
As with 2D coordinates, you can enter absolute coordinate values, which are
based on the origin, or you can enter relative coordinate values, which are
based on the last point entered. To enter relative coordinates, use the @ sign
as a prefix. For example, use @1,0,0 to enter a point one unit in the positive
X direction from the previous point. To enter absolute coordinates at the
Command prompt, no prefix is necessary.
Enter 3D Cartesian Coordinates
To enter absolute coordinates (3D)
 At a prompt for a point, enter coordinates in the tooltip using the following
format:
#x,y,z
If dynamic input is turned off, enter coordinates on the command line
using the following format:
x,y,z
To enter relative coordinates (3D)
 At a prompt for a point, enter coordinates using the following format:
@x,y,z
Enter Cylindrical Coordinates
3D cylindrical coordinates describe a precise location by a distance from the
UCS origin in the XY plane, an angle from the X axis in the XY plane, and a
Z value.
Cylindrical coordinate entry is the 3D equivalent of 2D polar coordinate entry.
It specifies an additional coordinate on an axis that is perpendicular to the
XY plane. Cylindrical coordinates define points by a distance in the XY plane
Use Precision Tools | 163