There are several aspects to the investigation of the properties of quadrilaterals.
- Each of the special quadrilaterals possesses a unique set of properties. Students can 'discover' these if they are given good activities and useful tools. They then need to retain the understanding of the properties for future use.
- The descriptions of properties are loaded with geometrical terms and it is important that students understand what these mean. Further elaboration can be found in The Language of Geometry.
At this stage of their mathematical development, most students view squares and rectangles as different shapes, rather than seeing that a square is just a special rectangle (and a special rhombus).