La géométrie en vers techniques is exactly what its title promises: the theorems of elementary geometry rendered into French mnemonic verse by Desrois, sometime dean of Mortain, on the theory that a proposition that rhymes is a proposition remembered.
It is a tiny, delightful monument to the pedagogical ingenuity of another age — Euclid as poetry, quite literally. Download the free EPUB and learn a theorem you can recite.