Did you know you can draw a huge number of infinite heights? The students’ realization tree of the heights of a triangle

In this paper we report on the analyses of the mathematical discourse of 7th grade students about the solution of a task on the recognition of the heights of a triangle. our aim is to describe through the commognitive lens the realizations that appear in the mathematical discourse of the classroom and to observe possible interactions between them. For this purpose, we construct and compare the expected and the actual students' realization trees, showing the richness of the realizations addressed by the participants in the mathematical discourse.