Cramer–Castillon problem

In geometry, the Cramer–Castillon problem is a problem stated by the Genevan mathematician Gabriel Cramer solved by the Italian mathematician, resident in Berlin, Jean de Castillon in 1776.

Centuries before, Pappus of Alexandria had solved a special case: when the three points are collinear.

But the general case had the reputation of being very difficult.

[2] After the geometrical construction of Castillon, Lagrange found an analytic solution, easier than Castillon's.

In the beginning of the 19th century, Lazare Carnot generalized it to