... (referred to in introduction to SL), CS (referred to in introduction to SL), QP (referred to in introduction to SC I). In the course of the texts themselves, the author refers to further worksno ... captures the varia. There aregenerally speaking two types of issues involved: the shape of the figure, and the assignment of the letters. I try to discuss first the shape of the figure, startingfrom the ... difficult to specify, and it seems to do mostly with the differentemphasis on the task set to the geometer. In a theorem, the task is to judge the truth of a result, while in a problem the task is to...