A well-known Persian manuscript on tilings which is now in the Bibliotheque Nationale in Paris
contains a number of geometrical constructions which are unusual in the sense that constructions of
this type occur only very rarely in medieval Islamic mathematical texts. These unusual
characteristics of these constructions will be discussed in the paper. In all likelihood,
their authors were not learned mathematicians who had been trained in the Euclidean style,
but craftsmen without "rigorous" mathematical training but with a strong intuitive geometrical insight.
We will also offer some thoughts on the relationship between these craftsmen and scholarly mathematicians and astronomers.