Activity Overview
This activity investigates concepts such as the shortest distance between two points in a plane, and the shortest distance between a line and a point not on the line. The analytical explanation of these concepts is supported with visual illustrations.
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 27 - 30 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
Draw two segments sharing an endpoint
Measure the lengths of the two segments and find the sum
Drag the point on the segments until the sum of the segments is at its lowest possible value
Understand how the shortest distance between two points is a straight line
Draw a line, a point not on the line, and a segment connecting them
Find the location of the point on the line such that the length of the segment is the shortest
Draw a line, two points not on the line, and segments that connect the points to one point on the line
Note the relationship between the angles formed when the sum of the segments is minimum
After the Activity
Review student results:
As a class, discuss questions that appeared to be more challenging
Re-teach concepts as necessary