The systems used for naming and classifying plane shapes are simple and logical, although some students find them complex.
In particular, when the definitions of quadrilaterals are considered inclusive, the concept can be quite challenging for students to understand. You can find a comprehensive list of quadrilateral definitions and properties on the BBC Bitesize website.
The naming and classification systems can be made meaningful to students through activities such as making models and mobiles or creating Venn and tree diagrams. These classroom activities build bridges from the informal interpretations encountered in the early years through to more formal approaches.
There are several different ways to classify simple polygons, using the number of sides, the length of sides, the sizes of angles and other properties.