We consider that, during the CSA period, the teaching of geometry must assume the two aims of mathematics education: mathematics as a basic service subject and mathematics for its own sake.
Mathematicians argue that (Euclidean) geometry is the (main) theory of space.
Mathematics curricula for the compulsory period are designed as if the mathematical point of view about geometry teaching could solve by itself all the main spatial needs of useful spatial representations in our society.
For 20 years, many French researchers have studied various didactic phenomena in the teaching and learning processes of geometry. These studies have made explicit the difficulties met by secondary school pupils in the learning process especially. But, regarding the teaching process, we are now convinced that the treatment of spatial abilities is the main source not only of many of the further learning difficulties met by secondary school pupils, but also of some of the main deficiences in spatial representation needs in everyday life.