Education Technology

Circumscribing a Circle About a Triangle

Subject Area
Math: Geometry: Circles
Math: Geometry: Triangles
Level
9-12
Activity Time
20 Minutes
Software
TI Connect™
TI Calculator
TI-84 series
Resource Types
Lessons

Circumscribing a Circle About a Triangle

Activity Overview

In this activity, students use the distance of the circumcenter of a triangle to each vertex of the triangle as the radius and draw a circle using the circumcenter as the center. 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 23-24 from the attached PDF file for your class
  • During the Activity

    Distribute the pages to your class.

    Follow the Activity procedures:

  • Send the figure from Activity 9 saved as an APP VAR via the TI-Navigator

  • Draw a triangle
  • Draw the perpendicular bisector of each side of the triangle
  • Locate the circumcenter
  • Find the distance from the circumcenter to a vertex of the triangle
  • Draw the circumcircle of the triangle
  • After the Activity

    Review student results:

  • As a class, discuss questions that appeared to be more challenging
  • Re-teach concepts as necessary
  • icon-download-lm
    Download Files
    Subject Area
    Math: Geometry: Circles
    Math: Geometry: Triangles
    Level
    9-12
    Activity Time
    20 Minutes
    Software
    TI Connect™
    TI Calculator
    TI-84 series
    Resource Types
    Lessons
    iPad is a trademark of Apple Inc., registered in the U.S. and other countries.
    Vernier EasyData,Vernier EasyLink and Vernier EasyTemp are registered trademarks of Vernier Science Education.