Education Technology

Equations of Circles

Subject Area
Math: Geometry: Circles
Level
9-12
Activity Time
90 Minutes
Software
TI Connect™
TI Calculator
TI-84 series
Other Materials
This is Activity 29 from the EXPLORATIONS Book:
Cabri™ Jr.: Interactive Geometry Activities and Investigations.
Resource Types
Lessons

Equations of Circles

Activity Overview

In this activity, students will explore the relationship among the location of the center of the circle, the radius of a circle, and the equation of a circle in a plane. They will also investigate the relationship between the points inside, on, and outside a circle, and the equation of the circle.

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 197 - 198 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 circle in the coordinate plane and identify its equation, center, and radius
  • Investigate any relationships that exists between the radius, the coordiantes of the center, and the equation of a circle
  • Construct another circle inside the first one
  • Drag points inside the first circle and the relationship between the equations of the two circles
  • 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: Circles
    Level
    9-12
    Activity Time
    90 Minutes
    Software
    TI Connect™
    TI Calculator
    TI-84 series
    Other Materials
    This is Activity 29 from the EXPLORATIONS Book:
    Cabri™ Jr.: Interactive Geometry Activities and Investigations.
    Resource Types
    Lessons
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