Date: Apr 1, 2011 2:57 PM
Author: Michael de Villiers
Subject: Hierarchical Quadrilateral Tree
Free dynamic Sketchpad 4 and Sketchpad 5 sketches that illustrate a Hierarchical Quadrilateral Tree can be downloaded from Sketchpad Exchange at http://sketchexchange.keypress.com/sketch/view/132/hierarchical-quadrilateral-tree
It shows the hierarchical relationships between several quadrilaterals as well as some of their their properties. Apart from the familiar ones, it includes isosceles trapezoids, cyclic & circumscribed quadrilaterals.
Hope teachers find it useful.