Karel Petr (; 14 June 1868, Zbyslav,

Austria-Hungary Austria-Hungary, often referred to as the Austro-Hungarian Empire,, the Dual Monarchy, or Austria, was a constitutional monarchy and great power in Central Europe between 1867 and 1918. It was formed with the Austro-Hungarian Compromise of ...

– 14 February 1950,

Prague Prague ( ; cs, Praha ; german: Prag, ; la, Praga) is the capital and largest city in the Czech Republic, and the historical capital of Bohemia. On the Vltava river, Prague is home to about 1.3 million people. The city has a temperate ...

Czechoslovakia , rue, Чеськословеньско, , yi, טשעכאסלאוואקיי, , common_name = Czechoslovakia , life_span = 1918–19391945–1992 , p1 = Austria-Hungary , image_p1 ...

) was a Czech

mathematician A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, structure, space, models, and change. History On ...

. He was one of the most renowned Czech mathematicians of the first half of the 20th century.

Biography

Petr is known for the

Petr–Douglas–Neumann theorem In geometry, the Petr–Douglas–Neumann theorem (or the PDN-theorem) is a result concerning arbitrary planar polygons. The theorem asserts that a certain procedure when applied to an arbitrary polygon always yields a regular polygon having the s ...

plane geometry Euclidean geometry is a mathematical system attributed to ancient Greek mathematician Euclid, which he described in his textbook on geometry: the '' Elements''. Euclid's approach consists in assuming a small set of intuitively appealing axioms ...

, which he proved in 1905 (in Czech) and in 1908 (in German). It was independently rediscovered by

Jesse Douglas Jesse Douglas (3 July 1897 – 7 September 1965) was an American mathematician and Fields Medalist known for his general solution to Plateau's problem. Life and career He was born to a Jewish family in New York City, the son of Sarah (née ...

in 1940 and by B H Neumann in 1941.

Eduard Čech Eduard Čech (; 29 June 1893 – 15 March 1960) was a Czech mathematician. His research interests included projective differential geometry and topology. He is especially known for the technique known as Stone–Čech compactification (in topolo ...

was a doctoral student of Petr at

Charles University ) , image_name = Carolinum_Logo.svg , image_size = 200px , established = , type = Public, Ancient , budget = 8.9 billion CZK , rector = Milena Králíčková , faculty = 4,057 , administrative_staff = 4,026 , students = 51,438 , undergr ...

in Prague. Petr's doctoral students also included

Bohumil Bydžovský Bohumil Bydžovský (14 March 1880, in Duchcov – 6 May 1969, in Jindřichův Hradec) was a Czech mathematician, specializing in algebraic geometry and algebra. Education and career Bydzovsky in 1898 completed his Abitur at the Academic Gymnasiu ...

and

Václav Hlavatý Václav Hlavatý (27 January 1894 – 11 January 1969) was a noted Czech- American mathematician, who wrote on the theory of relativity and corresponded extensively with Albert Einstein on the subject. In particular, Hlavatý solved some very diff ...

References

External links

* 1868 births 1950 deaths People from Kutná Hora District People from the Kingdom of Bohemia Czech mathematicians Charles University alumni Academic staff of Charles University Mathematicians from Austria-Hungary {{Czech-bio-stub