Abstract
The article is focused on the classifications of parallelograms and their meaning for a deeper understanding of the concept itself and its individual special cases. The procedures of classifications described above are suitable for pupils at middle schools, the utilization rate depends on the level of pupils and furthermore also on the time possibilities.
Included examples also lead to discovering and learning about quadrilaterals that are not parallelograms. Great emphasis is placed on finding connections and relationships among quadrilaterals.