Turn (geometry)
![Counterclockwise rotations about the center point where a complete rotation is equal to 1 turn](/Images/godic/202502/18/Angle-fractions0014.png")
![The circumference of the unit circle (whose radius is one) is 2π.](/Images/godic/202502/18/2pi-unrolled0014.gif")
![An arc of a circle with the same length as the radius of that circle corresponds to an angle of 1 radian. A full circle corresponds to a full turn, or approximately 6.28 radians, which are expressed here using the Greek letter tau (τ).](/Images/godic/202502/18/Circle_radians_tau0015.gif")
A turn is a unit of plane angle measurement equal to 2π radians, 360° or 400 gon. A turn is also referred to as a revolution or complete rotation or full circle or cycle or rev or rot.
A turn can be subdivided in many different ways: into half turns, quarter turns, centiturns, milliturns, binary angles, points etc.