Polar coordinate system

The polar coordinate system is a way to locate points in a plane using a center point (called the origin) and a distance and angle. Instead of using x and y coordinates, each point is described by its distance from the origin (radius, r) and the angle (theta, θ) measured from a fixed reference direction, usually the positive x-axis. This system is especially useful for representing circular or spiral shapes. To find a point, measure how far it is from the center and rotate from the reference line by the specified angle.