The aim of this applet is to exhibit that for u, v  ,                           From figure,

Instructions for using the Applet   To see this in the applet do the following : 1. Drag red point A and point B to select the vectors u and v 2. Click Start button to display rectangle OGHJ 3. Click Next button to observe rectangle OGHJ and OGIB are equal and rectangle OAEC and OFDC are equal