The applet below allows you
to move the corners of the common quadrilaterals to see how their
particular constraints allow them to change.
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?
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.