rectangular coordinate

A coordinate, i.e., a position or point, that (a) lies in a coordinate system that consists of a frame of reference established by a set of orthogonal axes, usually called the x-axis, the y-axis, and the z-axis, that intersect at a point, called the origin, and (b) is located by a distance from the origin parallel to each of the axes. Note 1: To locate a specific rectangular coordinate, measure a distance a along the x-axis, a distance b parallel to the y-axis, and a distance c parallel to the z-axis. The rectangular coordinate of this point is a, b, c. Note 2: To convert a two-dimensional rectangular coordinate to a polar coordinate, ρ = (a² + b²)^1/2 and θ = tan⁻¹ b/a. Note 3: Positive direction from the origin usually is to the right along the x-axis, upward along the y-axis, and toward the viewer along the z-axis to obtain a first quadrant projection of a point on an object that lies between the viewer and the three coordinate planes. Synonym Cartesian coordinate. See also convert, orthogonal...