%0 Journal Article %T Gr£¿bner Basis Convex Polytopes and Planar Graph %A Dang Vu Giang %J Mathematics %D 2012 %I arXiv %X Using the Gr\"obner basis of an ideal generated by a family of polynomials we prove that every planar graph is 4-colorable. Here we also use the fact that the complete graph of 5 vertices is not included in any planar graph. %U http://arxiv.org/abs/1202.4510v1