"All squares are rectangles!?!? - do you agree? What else can we say about quadrilaterals?"Look at quadrilaterals like you never have done before! Using dynamic geometry (geogebra) or the applet below, experiment with the limits of the quadrilaterals, determine which is which and then which quadrilateral is a subset of which other quadrilateral. Work towards a quadrilateral Venn diagram the tells the whole truth!