EJMT Abstract

The article focuses on deepening the content knowledge of area and perimeter at secondary school via an isoperimetric issue supported by GeoGebra diagrams. The text introduces the isoperimetric problem, introduces and analyzes the survey held on the isoperimetric issue at Czech secondary schools, and provides an ICT support to the secondary school instruction related to the isoperimetric problem: GeoGebra diagrams on area and perimeter interdependence, with a track to volume and surface upgrade.