Coordinate

1. A thing of the same rank with another thing; one two or more persons or things of equal rank, authority, or importance.
Cartesian coördinates .
See under Cartesian.
Geographical coördinates ,
the latitude and longitude of a place, by which its relative situation on the globe is known. The height of the above the sea level constitutes a third coördinate.
Polar coördinates ,
coördinates made up of a radius vector and its angle of inclination to another line, or a line and plane; as those defined in (b) and (d) above.
Rectangular coördinates ,
coördinates the axes of which intersect at right angles.
Rectilinear coördinates ,
coördinates made up of right lines. Those defined in (a) and (c) above are called also Cartesian coördinates.
Trigonometrical coördinates or Spherical coördinates ,
elements of reference, by means of which the position of a point on the surface of a sphere may be determined with respect to two great circles of the sphere.
Trilinear coördinates ,
coördinates of a point in a plane, consisting of the three ratios which the three distances of the point from three fixed lines have one to another.