Felix Klein
Felix Christian Klein was a German mathematician and mathematics educator, known for his work in group theory, complex analysis, non-Euclidean geometry, and the associations between geometry and group theory. His 1872 Erlangen program classified geometries by their basic symmetry groups and was an influential synthesis of much of the mathematics of the time.
25 April 1849
Born on the same birth day (25 April): Abdalla Uba Adamu • Jason Lee (actor) • Karel Appel • Luise Adolpha Le Beau • Martin Koolhoven • Mort Weisinger • Nicolas Oudinot • Walter de la Mare
Born in the same month (April 1849): William R. Day