Karel Petr

Karel Petr (Czech: [ˈkarɛl ˈpɛtr̩]; 14 June 1868, Zbyslav, Austria-Hungary – 14 February 1950, Prague, Czechoslovakia)^[1] was a mathematician from Bohemia in Austria-Hungary and later Czechoslovakia.

Karel Petr

Biography

Petr is known for the Petr–Douglas–Neumann theorem in plane geometry, which he proved in 1905 (in Czech)^[2] and in 1908 (in German).^[3][4] It was independently rediscovered by Jesse Douglas in 1940^[5] and by B H Neumann in 1941.^[4][6]

Eduard Čech was a doctoral student of Petr at Charles University in Prague. Petr's doctoral students also included Bohumil Bydžovský and Václav Hlavatý.^[7]