# Polar Coordinates

Polar coordinates are a two-dimensional coordinate system in which points in two dimensions are given by an angle and a distance from the origin.

Polar coordinates is a high school-level concept that would be first encountered in a pre-calculus course. It is listed in the California State Standards for Trigonometry.

### Prerequisites

Angle: | An angle is a measure of the amount of rotation about the point of intersection of two lines or line segments that is required to bring one into correspondence with the other. |

Cartesian Coordinates: | Cartesian coordinates are the usual coordinate system, originally described by Descartes, in which points are specified as distances to a set of perpendicular axes. Also called rectangular coordinates. |

Radius: | The radius of a circle is the distance from its center to its circumference or from the center of a sphere to its surface. The radius is equal to half the diameter. |