The perpendicular bisector of a segment is a line that intersects a segment at 90 degrees and divides the line segment into two congruent parts (hence bisector). In the activity below, students will construct a perpendicular bisector using GeoGebra and the free hand tools, that is there is no pre-made sketch. It is assumed that students can create lines, parallel lines and measure angles (demonstrations for help). The objectives of this lesson is for students to develop definitions for the Perpendicular Bisector Conjecture and its Converse.

I will also include a video at the bottom of the total construction. Students will investigate properties of perpendicular bisectors.

Here is the construction WS

This is a Java Applet created using GeoGebra from - it looks like you don't have Java installed, please go to

Nicholas F. Bennett, Created with GeoGebra

Below is a video to construct a perpendicular bisector using a compass and straight edge.