University of Cambridge
University of Cambridge: Nrich: Virtual Geoboard
Use this virtual geoboard to explore the attributes of various polygons. This would work well on an interactive whiteboard.
McGill University
Ear Cutting for Simple Polygons: Introduction
This site gives the definitions for various polygon-related material.
Curated OER
Ear Cutting for Simple Polygons: Introduction
This site gives the definitions for various polygon-related material.