About geometry and spheres
This paper is about certain geometry and spheres, the main theorem being "In whatever triangle ABC, straight lines Aa, Bb, Cc are drawn from the angles to the opposite sides so that they all meet at some point O, then they will always have the following property AO/Oa ∙ BO/Ob ∙ CO/Oc = AO/Oa + BO/Ob + CO/Oc + 2."
Original Source Citation
Mémoires de l'académie des sciences de St.-Petersbourg, Volume 5, pp. 96-114.
Opera Omnia Citation
Series 1, Volume 26, pp.344-358.