The work is the second part of a previous one, published in the same magazine (Contextos III/6, pp. 163-176) and it is exclusively about a very important aspect the fractals in Geometry. The relation M = RD which characterizes these structures, is studied in the first part, analysing 2 specific circumstances. The second one deals with the basic theorem, according to which it is possible to build certain fractals with a previously fixed dimension. The development has been done following an intuitive and inaccurate pattern, taking "Sierpinski Gasket" as an example of a better known structure. Finally, the figure of 2 fractals are offered together with their respective computer ...