# cylindrical coordinates

Cylindrical coordinates are a coordinate system in which a point is located by its height *z* above a reference plane and the polar
coordinates of its projection onto that plane, (*r*, *θ*).
(*r*, *θ*, *z*) can be related to rectangular
Cartesian coordinates by *x* = *r* cos*θ*, *y* = *r* sin*θ*, and *z* = *z* (where the original reference plane corresponds to the *xy*-plane).