3 Bisect an Arc
- Draw an .
- Draw a line () that connects the two points of the arc (now, the line).
- Set your compass to approximately ¾ of the length of the line. (The important thing is to set it to more than half. The further past half way, the more accurate, but the larger the space required becomes.)
- Keeping this distance set on your compass, swing arcs from both ends of the line, directed towards the centre.
- Draw a line through the two intersection points of the arcs.
a portion of a circumference
a straight line from 2 points on a circumference
to divide in half