Properties of triangles for which certain angles have a ratio between themselves
According to Jacobi, a treatise with this title was read to the Berlin Academy on September 22, 1763. According to St. Petersburg Academy records, it was presented to that Academy on December 21, 1763.
Euler derives properties of a triangle based on relationships between the angles of the triangle; these properties are polynomials that the (lengths of the) sides must satisfy.
Original Source Citation
Novi Commentarii academiae scientiarum Petropolitanae, Volume 11, pp. 67-102.
Opera Omnia Citation
Series 1, Volume 26, pp.109-138.