Professor of the University of Athens, Ioannis Arachovitis, forewords.

Euclid 's work "Dedomena" is the second of his purely geometrical works (after "Elements") to survive. It was written by the great mathematician several years after the "Elements" and is a collection of propositions whose proofs rest on theorems or constructions of the "Elements".

"Data" is a well-structured geometric set, without ambiguities and gaps. The study of the work arouses not only the interest, but also the admiration of scholars.