In mathematics, the angle of rotation is a measurement of the amount, the angle, by which a figure is rotated counterclockwise about a fixed point, often the center of a circle. A clockwise rotation is considered a negative rotation, so that for instance a rotation of 310° (counterclockwise) can also be called a rotation of –50° (since 310°+50°=360°, a full rotation). A counterclockwise rotation of more than one complete turn is normally measured modulo 360°, meaning that 360° is subtracted off as many times as possible to leave a non-negative measurement less than 360°.