Set a compass to draw a circle with a radius that's more than half the length of the line segment but less than the whole length. Put the compass point at one end of the segment and draw an arc above...
The perpendicular bisector of a line segment AB is the straight line perpendicular to AB through the midpoint of AB.
One ! The word 'bisect' means to cut in two !
there are infinitely many segments in a line.
one