Finsler–Hadwiger_theorem
Finsler–Hadwiger theorem
Describes a third square derived from any two squares that share a vertex
The Finsler–Hadwiger theorem is statement in Euclidean plane geometry that describes a third square derived from any two squares that share a vertex. The theorem is named after Paul Finsler and Hugo Hadwiger, who published it in 1937 as part of the same paper in which they published the Hadwiger–Finsler inequality relating the side lengths and area of a triangle.[1]