This article presents a didactic experience carried out in flipped classroom mode in a lower secondary school. This teaching method, which can be summarized as "theory at home and homework at school", can be considered as innovative since it allows introducing new technologies in the classroom, promoting a conscious use of them. The experience, focused on the Pythagorean theorem, thrilled the students. The article reports on all the lessons on this theme: the introductory activity, the formulation of the theorem, its different proofs, the inverse implication of the theorem, various exercises, and the test. Compared to a more traditional introduction, the students were more motivated and their learning appeared to be more rooted.