Education Technology


Midpoint of a Segment

Activity Overview

Students review the basic geometry definitions of segment and midpoint, and learn to use drawing and measurement tools. They explore changes in measurements as the figure is altered. 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 pages 3-4 from the attached PDF file for your class
  • During the Activity

    Distribute the pages to your class.

    Follow the Activity procedures:

  • Construct a segment
  • Find the midpoint of the segment
  • Measure the segment and each half
  • Alter the length of the segment and measure the segments


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

    Review student results:

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