|Cartesian coordinates See also spherical coordinates a pair of coordinates for locating a point in a plane by means of the length of a radius vector, r, which pivots about the origin to establish the angle, θ, that the position of the point makes with a fixed line. Usually written (r, θ)|
system of locating points in a plane with reference to a fixed point (origin) and an axis through that point. The coordinates are written (r,theta), in which r is the distance from the origin to any desired point and theta is the angle made by the vector r and the axis. A simple relationship exists between Cartesian coordinates given in terms of two reference axes (x,y) and the polar coordinates (r,theta), namely: x = r cos theta, and y = r sin theta
Learn more about polar coordinates with a free trial on Britannica.com.