Add to ORKGIn this paper we introduce a model to 'read' the impact of e-learning technologies on the teaching/learning process, usually interpreted through the “didactical triangle” - knowledge, student, teacher (Chevallard, 1985). The idea we present here starts increasing the number of actors -that are author (A), student/s (S), tutor (T), mathematical knowledge (M) - and makes the model to become three-dimensional, passing from a triangle to a tetrahedron. The mediation of technology is represented by a sphere inscribed in the tetrahedron. The tangent point of the sphere with each face of the tetrahedron allows us to look at the relations among the three actors (the vertices of the face) in the e-learning environment and then how they can be tr...