To Observe, to Deduce, to Reconstruct, to Know

This paper deals with a didactic experience gained in courses that are part of the first year of studies for the Schools of Architecture and Design at Politecnico di Milano. One of the themes of these courses concerns geometric problems, in order to introduce students to 3D space. The peculiarity of the didactic method used is, first of all, to induce the student to observe the real object by identifying its geometric characteristics (symmetries, proportions, contours, and surfaces enveloping it). Subsequently, the goal is to teach how to translate the observed form into mathematical language and to draw it on the computer, using a suitable tool of Computer Graphics. The method, consequently, allows to deepen and appreciate, with greater awareness, the characteristics of the studied form. To illustrate the process, we will present applications related to significant and fascinating objects of interest for the public we are addressing.