These activities are taken from the Journal of Education, Volume 178, No.2, 1996 (pp. 15-32)
A ROLE FOR TECHNOLOGY IN MATHEMATICS EDUCATION
By: Albert A. Cuoco and E. Paul Goldenberg

I have created the examples presented in the article using The Geometer's Sketchpad. I then converted them to JavaSketchpad for exploration in an Internet Browser. Let's begin exploring. First a few rules for using JavaSketchpad:

1. The red points indicate points that can be manipulated or moved within the sketch. Try dragging these points around in each sketch to see how it impacts the plotted points
2. Clicking the red 'X' at the bottom right of the sketch refreshes the sketch (erases traces). This only works when there are traces on the sketch and will not work when loci are present or no traces are present
3. The 'M' Button stretches or shrinks the scale of the grid (This will be important as the point we are wanting to look at is beyond our range so you will have to shrink the scale often.) I am working on a fix for this problem
4. I've included boxes that you can click to perform various actions especially in the first sketch
5. Download the entire file located here in GSP 4.0+ format: cuocogoldenberg.gsp
6. View the text document of a possible assignment scenario here: April 14th, 2006
7. Finally, view a GSP file that Michael, Jay, Noel, and I came up with as an extension: heron_sine_area.gsp

1a. Using the following sketch contruct triangle ABC and random point P on segment AB. Construct a line through P that is perpendicular to AC through a point D. Construct a line through P that is perpendicular to BC through a point E.

1b. Where should P be located along AB to minimize DE? Try Sliding P back and Forth. If you at first do not see the point (AB, DE) in the upper right (1st) quadrant drag point 'M' to the left to see point (AB, DE) Then try dragging P back and forth again.