Quadrilaterals: SketchPad Files
Some of my favourite work here - lots to come too!
(1). All of these filenames in this page are LONG! - Therefore, if you want to preserve these (Because Version 3.* of SketchPad does not use long filenames) you must either RIGHT-CLICK on the file links within the above directories and then choose "Save Target As...". This allows you to save the file directly to a disk/drive or after using a LEFT-CLICK select the "Save this file to disk" Option Box rather than selecting the "Open this file from its current location". If you choose this last option then Geometer's SketchPad will automatically open - if you have it! - but then after viewing the file if you then try to save it you will not be able to use a long filename.
D - Bisect Quadrilateral
Given with a full explanation of this Theory
D - Collinearity Property of Triangle with 3 Parallelograms .gsp
An amazing Theorem - It can be built up from a solitary Triangle and transversal line to help the explanation. It has to be seen to be believed - a real Gem!
D - Congruent Cyclic Quadrilaterals Using Orthocentres of 4 Internal Triangles.gsp
Another striking Theory that can be built up in stages - It's interesting to show only the green apexes and try to understand what's happening as they are dragged around!
D - Parallelogram
from a Quadrilateral.gsp
An impressive result using Equilateral Triangles
D - Quadrilateral Theorem
An Angle Bisector result for a general Quadrilateral
D - Trisect Rectangle Area.gsp
A couple of constructions needed here -both explained.