To bisect a segment means to draw the object that bisects it, or passes through its midpoint. Here it will be shown how to draw the line that bisects
Place a compass with its pointy end at one of the segment's end-points. Draw a large arc that intersects the segment further away than the midpoint.
Keep the compass set on the same length and place its pointy end at the other end of the segment. Draw another large arc across the segment.
If the arcs have been drawn large enough, they will now intersect each other twice. If they don't, extend them. Next use a ruler to draw a line through the two points where the arcs intersect each other.
The last step is to erase the arcs and draw an arrow on each end of the line.