Education Technology

Perpendicular Bisector of a Line Segment

Published on 06/09/2008

Activity Overview

Students learn to draw a segment and its perpendicular bisector. They understand right angles and congruent segments. Students observe that changing the length or orientation of the segment changes the perpendicular bisector. NCTM Geometry Standard covered: Analyze characteristics and properties of 2- and 3-dimensional geometric shapes and develop mathematical arguments about geometric relationships.

Before the Activity

  • Install the Cabri Jr. App on the students' graphing calculators using TI Connect™, a TI Connectivity Cable, and the Unit-to-Unit Link Cable
  • Set up the TI-Navigator™ system
  • See the attached PDF file for detailed instructions for this activity
  • Print page 6 from the attached PDF file for your class
  • During the Activity

    Distribute the page to your class.

    Follow the Activity procedures:

  • Draw a line and its perpendicular bisector
  • Measure the two halves of the segment
  • Measure an angle formed
  • Change the length and position of the segment
  • Observe that the measurement of the segment changes but the angle measure remains 90?


  • TI-Navigator activity:
  • Use Screen Capture to observe and assess individual progress in drawing and exploring line bisectors
  • After the Activity

    Review student results:

  • As a class, discuss questions that appeared to be more challenging
  • Re-teach concepts as necessary