Learning Basic Commands to Get Started - AutoCAD 2011 and AutoCAD LT 2011: No Experience Required - page 49

FiGuRE 2.14 The Relative Cartesian Coordinate System
Relative Polar Coordinates
This system requires a known distance and direction from one point to the next.
Calculating the distance is straightforward: it's always positive and represents the
distance away from the first point that the second point will be placed. The direc-
tion requires a convention for determining an angle. AutoCAD defines right (toward
three o'clock) as the default direction of the 0° angle. All other directions are deter-
mined from a counterclockwise rotation (see Figure 2.15). On your screen, up is
90°, left is 180°, down is 270°, and a full circle is 360°. To let AutoCAD know that
you're entering an angle and not a relative y-coordinate, use the less-than symbol
(<) before the angle and after the distance. Therefore, in the previous example, to
designate a point 8 units to the right of the first point, you would enter @8<0 or sim-
ply 8<0 when the Dynamic Input tool is active.
NOTE Use the relative polar Coordinates method to draw a line from
the first point when you know the distance and direction to its next point.
enter data using this form: @distance<angle .
using the Direct Distance Method
You can also draw lines by placing the cursor at any angle relative to the last
point and entering a distance value at the command prompt. The line is drawn
from the last point toward or through the cursor location at the length speci-
fied. The Direct Distance method is often used when either Ortho mode or Polar
Tracking is turned on.