DefinitionPolar coordinates are based on a radius and an angle in a plane. Cylindrical coordinates add a height dimension to polar coordinates. Points in 3D space are exactly defined by their radius, or distance up off the x-y plane, their polar angle, and their azimuthal angle by using spherical coordinates. Example: A point (r,θ,z) with cylindrical coordinates is equal to (rcosθ,rsinθ,z) in Cartesian coordinates.