Here is a calculator to compute the sides of a right triangle using the ( m2 - n2 , 2mn , m2 + n2 ) formula  - just enter values for m and n or use the scroll bars to change their values. Note that m will always be greater than n. Changing the value of t  will result in linear multiples of the original triple.

This applet requires Suns Java VM 2 which your browser may perceive as a popup. Which it is not. If you want to see the applet work, visit Suns website at http://www.java.com/en/download/index.jsp, download and install Java VM and enjoy the applet.

Applet copyright Interactive Mathematics Miscellany and Puzzles