An interactive applet and associated web page showing the properties of a quadrilateral. The applet shows a quadrilateral with draggable vertices. The web page has an extensive list of the various types of quadrilateral and links to other pages and applets illustrating each type.

Applet can be enlarged to full screen size for use with a classroom projector. After use in the classroom, student can access it again from any web browser at home or in the library with no login required.

This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.