Donald Coxeter was a renowned Canadian mathematician, best known for his work in geometry and the study of polytopes. He made significant contributions to the field of discrete geometry, particularly in the classification of regular polytopes and symmetry. His research has influenced various areas of mathematics and has applications in fields like computer graphics and crystallography. Coxeter was born on February 9, 1907, and had a long and distinguished career, teaching at University of Toronto for many years. He published numerous papers and books, including the influential text "Regular Polytopes." His legacy continues to inspire mathematicians and students interested in the beauty of geometric structures.