Date: Jun 6, 2013 4:54 AM
Author: Michael de Villiers
Subject: Dynamic Geometry Sketches Site Updated

My 'Dynamic Geometry Sketches' site available at: has been updated with the following:
1) A generalization of a parallelogram theorem to parallelo-hexagons, and Douglas' theorem for polygons. (New)
2) Hierarchical Quadrilateral Tree. (Updated)
3) Van Aubel's theorem and some generalization. (Updated)
4) Some unproved conjectures. (Updated)

For students: Dynamically explore, and make conjectures about the relations between the sides and major diagonals of a parallelo-hexagon and logically explain them at: