“The height challenge”: from the game in a dynamic geometry environment to the discussion of critical attributes of the figures

Abstract

The intertwining of conceptual and figural components is a fundamental feature of geometric thinking and constitutes an important didactic goal at all school levels. This article focuses on the heights of the triangles by framing the problem from a theoretical point of view and analyzing a didactic activity experimented in seventh grade classes. The activity is centered on an inquiring-game with digital feedback implemented in GeoGebra, followed by a class discussion. Through the analysis of extracts from the class discussion, the teaching potential of the design will be shown, with particular reference to the evolution of the students’ personal concept image.