A problem of geometry proposed publicly by an anonymous geometer
Almost certainly Euler's shortest publication, this paper consists of 8 lines in the Nova Acta Eruditorum. As the title suggests, the entire work is the proposal of a geometry problem. Specifically, the problem involves finding all curves that have a certain reflection property that Euler describes. Euler himself solved this problem two years later, in E106.
Original Source Citation
Nova acta eruditorum, Volume 1745, pp. 523.
Opera Omnia Citation
Series 1, Volume 27, pp.50-50.