Bisection
Introduction
Problem solving with geometric constructions often involves dividing a given
entity. Dividing geometric figures into two equal parts is called bisecting.
The line that bisects the figure is known as a bisector. You should know
how to bisect different geometric figures to accurately solve drafting
problems.
Bisecting lines
To bisect a line or arc, use this table:
or circular arcs
Step
Action
1
With a given arc or line (AB), use a compass set at a distance
greater than half the distance of the given line and draw equal arcs
above and below the given line.
2
Use a straightedge to join the intersections of the arcs. This
straight line locates the center of the given line or arc.
Figure 2-18 shows how to bisect a line or arc.
Figure 2-18.—Bisecting a line or
arc.
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