Movimento, percezione e dimostrazione

Summary. Geometry can be treated from a logical point of view, following the precise sequence of its statements, or from an intuitive or perceptive point of view, which is linked to a global understanding of geometrical objects. The balance between these two aspects is the core of geometrical education. In this paper we will show and discuss examples of proofs linked to diagrams or models, in which the argument is based on intuition. We will then see how the introduction of motion can give a major role to perception, seen as the skill to develop an argument based only on images and diagrams, almost without any linguistic support. But sometimes perception needs an "external control".