Definition of Terms, Continued
Points and lines
LINE: A straight line is the shortest distance between two points and is often
referred to simply as a line. If the length of a line is indefinite or without
fixed endpoints, its length is any distance you select. If the line has fixed
endpoints, mark them with small mechanically drawn cross hairs. Straight or
curved lines are parallel if the shortest distance between them remains
constant throughout their length. If a line is parallel to another line, use the
common symbol for parallelism (||). Lines that intersect at right angles (90°)
to each other are referred to as perpendicular. Indicate perpendicularity with
short lines intersecting at right angles (^ (singular) or ^s (plural)) or a small
square box at the apex (
) of the intersection.
Figure 2-2 shows common line terminology.
Continued on next page