A method of defining the location of points on a plane by their distances from two fixed perpendicular straight lines (axes). This concept can already be found in the works of Archimedes and Apollonius more than two thousand years ago, and even in those of ancient Egyptians. The idea was first developed in a systematic manner by R. Descartes and P. Fermat, in whose formulations the distance could only be positive or zero. The idea of imparting negative values to one or both these distances was proposed by I. Newton. G. Leibniz was the first one to name these distances "coordinates" . See Cartesian orthogonal coordinate system.