Hypermedia as a Means for Learning and for Thinking about Learning.

This paper is about the design and realization of an experimentation with a hypermedial system, IPER-3, facing the three 'classical' problems in the history of mathematics (trisection of the angle, quadrature of the circle, duplication of the cube) and some issues which have developed around them. The aim of the work is to study the opportunities provided by hypermedial systems in dealing with topics of interest for the training of teachers and/or for class work, exploiting the possibility of a non-linear presentation, representation of heterogeneous pieces of information, modularization, increment and flexibility of use.