Question 110823
use a compass and make sure it is open to at least half the length of the segment


put the point of the compass on one end of the segment and draw arcs on either side of the segment


without changing the compass opening, move the point to the other end of the segment and again draw arcs on either side of the segment


the arcs should intersect on both sides of the segment
... draw a line connecting the arc intersections
... this line is the perpendicular bisector of the segment
... the line intersects the segment at the midpoint