Construction: Bisect a line segment
Construction: Bisect a line segment.
1.  Select compass tool.
2.  Click on point A then point B to set compass width, then click on A again to set compass in place.  
3.  Click on point A then point B again, then click on point B to set compass in place.  Both compasses should intersect above and below the line segment.
4.  Choose the point icon to mark the points where the compasses intersect.  Label points C and D.  
5. Draw a line segment between C and D.
6.  Mark the midpoint of AB with point E.