It is denoted by the symbol s. The Arc Length of a Circle is the length of circumference of the arc. Since the radius is half the diameter of a circle to find the radius simply divide the diameter by 2.
This is because.
The arc length formula. L e n g t h th 360 2 p r. The length more precisely arc length of an arc of a circle with radius r and subtending an angle th measured in radians with the circle center ie the central angle is. The arc length formula.