On the reduction of curved lines to the arcs of circles
Euler looks at the approximate rectification of pieces of curves if the lengths of the normals at the endpoints as well as the angles between these normals are given.
Original Source Citation
Novi Commentarii academiae scientiarum Petropolitanae, Volume 2, pp. 3-38.
Opera Omnia Citation
Series 1, Volume 27, pp.200-235.