This number is the minimum number of perfect squares that are needed to sum to any positive integer.
This number is the minimum number of perfect squares that are needed to sum to any positive integer. Both Abel and Ruffini proved that this number is the maximum degree polynomial for which there is a general algebraic solution. This number is the chromatic number of the sphere and is also the maximum number of colors needed to color a plane map such that no two regions sharing an edge have the same color. For 10 points, name this minimum number of faces of a regular polyhedron, the number of sides in a quadrilateral.
This number is the minimum number of perfect squares that are needed to sum to any positive integer.
{four}