The National Library of Virtual Manipulatives is a three-year NSF supported project to develop a library of uniquely interactive, web-based virtual manipulatives or concept tutorials, mostly in the form of Java applets, for mathematics instruction (K-8 emphasis). The project includes dissemination and extensive internal and external evaluation. For more information, please visit http://nlvm.usu.edu/en/nav/vlibrary.html.
This interactive web-based manipulative gives two dynamic illustrations of the Pythagorean Theorem, that the square on the hypotenuse of a right triangle is equal to the sum of the squares on the other two sides. These proofs by dissection are only two of literally hundreds of ways that people have found to demonstrate the validity of the theorem. Students who have played with rearrangements of shaped pieces may solve the puzzles rather quickly; those without any experience may need patience and perhaps some hints.
Java Applet Programming
Web Site Programming