Tessellation - Dynamic Geometry

The applet below allows you to move the corners of the central quadrilateral to see how any four-sided shape can tessellate (using rotation and reflection)

Work out what changes, and - more importantly - what stays the same, for the different quadrilaterals. Can you come up with a list of the special properties of each of these six shapes?

Sorry, the GeoGebra Applet could not be started. Please make sure that Java 1.4.2 (or later) is installed and active in your browser (Click here to install Java now)

Note: the kite shown here can be altered to make a 'delta' or arrowhead shape. While technically a different shape, apart from the presence of a reflex angle, its rules are the same as for a kite, so they are treated as the same for this demonstration.