Coordinates from a horizontal reference system which locate points by measuring their distance and angle of direction from a central point on a base line called a pole, centre, or origin.

A coordinate system based on a sphere.

A two-coordinate geometry in which position from an origin is specified by direction and distance, for instance, course and distance on a Mercator chart.

(n) A 2-D coordinate system used to locate a point in a plane by specifying a distance and an angle from the coordinate origin. When another distance normal to the coordinate origin is added, cylindrical coordinates can be specified.

An alternative system of marking a point on a plane by its radial distance (r) from an "origin" and a polar angle (f). Polar coordinates in 3-dimensional space use (r) and two polar angles (q,f) giving the direction from the origin to the point. When 3-dimensional polar coordinates overlap a cartesian (x,y,z) system, q is the angle between the line to the origin and the z-axis, while f is the angle (counter-clockwise when viewed from +z) between the projection of that line onto the (x,y) plane and the x-axis. Concerning (q,f), see also latitude and longitude, declination and right ascension, azimuth and elevation.

The coordinate system for the plane based on , , the distance from the origin and , and the angle between the positive axis and the ray from the origin to the point.

Either of two numbers that locate a point in a plane by its distance from a fixed point and the angle this line makes with a fixed line.

1. In the plane, a system of curvilinear coordinates in which a point is located by its distance from the origin (or pole) and by the angle Î¸ which a line joining the given point and the origin makes with a fixed reference line, called the polar axis. The relations between rectangular Cartesian coordinates and polar coordinates are where the origins of the two systems coincide and the polar axis coincides with the axis. 2. In space, same as spherical coordinates. See also cylindrical coordinates.