angular position is the angular coordinate of a location in polar coordinates, generally represented by the small Greek letter theta, θ . Although angular position is not a vector (the polar coordinate r contains the vector information), the time derivatives of the angular position, the angular velocity and the angular acceleration, are vectors, and are specified by both magnitude and direction. The angular position has only positive or negative magnitude. The usual convention is to measure the angle counterclockwise positive from the x-axis, in either degrees or radians.