Describing and defining quadrilaterals

This lesson develops the concept of naming and classifying quadrilaterals according to their properties. Students identify the minimal information required to define a quadrilateral. They sketch quadrilaterals with given conditions.

During the first part of the lesson students choose from the words ‘all’, ‘some’ or ‘no’ to make statements about quadrilaterals true. An example is where students have to choose between: ‘all, some or no’ rhombuses parallelograms. Reasons must be given to justify choices.

In the next part of the lesson students use six sets of property cards to draw quadrilaterals. They must decide what the minimum number of property cards is needed to uniquely define each quadrilaterals.

There are pre-lesson and post-lesson formative assessment tasks. Detailed teacher notes give suggestions on questioning and how to use the resources. Full solutions are given for each of the sections.

This is a concept development lesson from the Mathematics Assessment Resource Service, a collaboration between UC Berkeley and the Shell Centre team at the University of Nottingham. Further information on the collection is given here.