H. S. M. Coxeter

Harold Scott MacDonald "Donald" Coxeter CC (February 9, 1907 – March 31, 2003) is regarded as one of the great geometers of the 20th century. He was born in London but spent most of his life in Canada.He worked for 60 years at the University of Toronto and published twelve books. He was most noted for his work on regular polytopes and higher-dimensional geometries. He met Maurits Escher and his work on geometric figures helped inspire some of Escher's works, particularly the Circle Limit series based on hyperbolic tessellations. He also inspired some of the innovations of Buckminster Fuller.
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