Activity Overview
In this activity, students observe a special characteristic of the bisectors of the angles in a triangle. They test their conjecture by changing the size and shape of the triangle. 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 15-16 from the attached PDF file for your class
During the Activity
Distribute the pages to your class.
Follow the Activity procedures:
Draw a triangle using the App
Draw the bisector of each angle of the triangle
Locate the incenter of the triangle
Explore properties of the incenter
TI-Navigator activity:
Save the file and send it to students as an APP VAR for exploration and investigation in Activity 12
After the Activity
Review student results:
As a class, discuss questions that appeared to be more challenging
Re-teach concepts as necessary