Geometer's Sketchpad and Java Sketchpad

The Geometer's Sketchpad® is a Dynamic Geometry® exploration environment available for Macintosh® and PC computers from Key Curriculum Press. JavaSketchpad is software that facilitates development and distribution of mathlets by publishing sketches from The Geometer's Sketchpad® on the Internet.  The JavaSketchpad Developer Release 4 is integrated into Sketchpad version 4, or it can be downloaded independently from Key Curriculum Press.  Besides the downloadable software, the Key Curriculum site has detailed information about creating JavaSketchpad applets and a gallery of examples to explore.

Michael Mays is in the Department of Mathematics at West Virginia University.

Although JavaSketchpad requires a Java-enabled browser to view the sketches, you do not have to program in Java to create them.  Instead, you can build a sketch in The Geometer's Sketchpad Version 4 and save it in HTML format.  The sketch as saved in HTML looks like an old fashioned (pre-Version 4) gsp script, with calls to class files provided in the /jsp folder via parameter passing.  

Everybody draws a triangle as their first Sketchpad sketch.  If you have Sketchpad installed on your computer, you can click here to open a gsp sketch of a generic triangle.  Whether you have Sketchpad installed or not, you can click here to open the JavaSketchpad version.  Inspect the HTML code of Triangle.htm, and you will see the meat of the construction in the lines

<PARAM NAME=Construction VALUE="
{1} Point(127,64);
{2} Point(81,183);
{3} Segment(2,1)[color(0,0,128),thick];
{4} Point(183,185);
{5} Segment(4,2)[color(0,0,128),thick];
{6} Segment(1,4)[color(0,0,128),thick];
">  

which specify the initial placement of three points and three lines.  The figures at the right show how similar the results are. 

JavaSketchpad is a stand-alone product that can be used independently of  The Geometer's Sketchpad.  Key Curriculum Press grants the right to freely use JavaSketchpad applets in your own Web pages, provided you do so for non-commercial use only. Other permissions or rights to JavaSketchpad require a written agreement letter from Key Curriculum Press; contact Key Curriculum Press for more info.

Resource Notes

1. If your browser has an old version of the Java plug-in, you may need to download and install a current version in order to run some of the applets in this article. All of the applets have been tested and work with Version 1.4.2 of the Java Runtime Environment, Standard Edition, in Internet Explorer, Netscape, and Mozilla. You can download the current version (free) from Sun Microsystems.
2. You do not need to own The Geometer's Sketchpad® to read this article. However, to view source code for Sketchpad examples or to create your own examples, you do need this product. See the first paragraph of the Introduction for information about acquiring it.

Published August, 2003

© 2003 by Michael E. Mays