To draw a line at an angle, you need to specify how long a line you want to draw and specify the angle. Consider this point to be stationary at all times. In some CADD programs this point remains visible at the left bottom corner of the drawing area, while in others it is invisible. You can use this point as a reference to measure any distance in the drawing. Absolute coordinates are primarily used to adjust the alignment of diagrams in a drawing, to align one drawing with another or to make plotting adjustments.
Relative format is a way of measuring distances from the last point entered.
All measurements are taken the same way as the absolute coordinates, with the only difference being that the relative coordinates are measured from the last point entered instead of the origin point. This mode of measurement is frequently used for drawing because it is always convenient to place the drawing components relative to each other rather than a fixed reference point. The task table located at the end of the chapter shows some examples from leading CADD programs. A Prototype CADD Drawing A CADD program is designed to meet the needs of a vast number of individuals. It comes with a number of options that can be customized.