Education Technology

Properties of the Centers of a Triangle

Subject Area
Math: Geometry: Triangles
Level
9-12
Activity Time
90 Minutes
Software
TI Connect™
TI Calculator
TI-83 Plus Family
TI-84 Plus
TI-84 Plus Silver Edition
Other Materials
This is Activity 20 from the EXPLORATIONS Book:
Cabri™ Jr.: Interactive Geometry Activities and Investigations".
Resource Types
Lessons

Properties of the Centers of a Triangle

Activity Overview

Students investigate the sum of the measures of the interior angles of a triangle. This activity explores interior angles, and their relationship with the exterior angles of a triangle.

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
  • Use the TI-Navigator™ to transfer the attached Cabri Jr. AppVar files to each calculator
  • See the attached PDF file for detailed instructions for this activity
  • Print pages 125 - 127 from the attached PDF file for your class
  • During the Activity

    Distribute the pages to your class.

    Follow the Activity procedures:

  • Use the AppVar to go directly to the exploration section
  • Construct a triangle and its four centers
  • Adjust the construction to further investigate the circumcircle and orthocenter
  • After the Activity

    Review student results:

  • As a class, discuss questions that appeared to be more challenging
  • Re-teach concepts as necessary
  • Subject Area
    Math: Geometry: Triangles
    Level
    9-12
    Activity Time
    90 Minutes
    Software
    TI Connect™
    TI Calculator
    TI-83 Plus Family
    TI-84 Plus
    TI-84 Plus Silver Edition
    Other Materials
    This is Activity 20 from the EXPLORATIONS Book:
    Cabri™ Jr.: Interactive Geometry Activities and Investigations".
    Resource Types
    Lessons
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