Steps for constructing a segment bisector and/or finding a midpoint.
Step 1 - Using the Segment tool (located in the lines toolbox, the 3rd box from the left), create Segment AB.
Step 2 - Using the Circle with Center through Point tool, create Circle A. This should create a new point as well, Point C.
Step 3 - Using the Compass tool (located in the circles toolbox, the 6th box from the left), construct a new circle congruent to Circle A. To do this, click on Point A and then on Point C. You should now see a circle that is congruent to Circle A. Place it on Point B to create Circle B.
Step 4 - Using the Intersect tool (located in the "points" toolbox, the 2nd box from the left), click on Circle A and Circle B to construct the points of intersections of the two circles. These should be Points D and E.
*If Circle A and Circle B to not intersect, move Point C until the two circles overlap.
Step 5 - Use the Line tool, construct a Line DE.
Step 6 - Use the Intersect tool to create Point F, the midpoint of the segment.
At this point, you may add colors, dotted lines, etc. to help make your construction more useful. Move the various points around and make observations. What do you see?