Length of an arc of a circle (central angle in radians)


Circular arc is a segment of a circle, or of its circumference (boundary) if the circle is considered to be a disc. Central angle is an angle whose apex (vertex) is the center of a circle and whose legs (sides) are radii intersecting the circle in two distinct points and thereby subtending an arc between those two points whose angle is (by definition) equal to that of the central angle itself. It is also known as the arc segment’s angular distance. The length of an arc of a circle with central angle measured in radians, is given by multypling the central angle with the radius of the circle.

Related formulas


sThe length of the arc of the circle (m)
θThe central angle (radians)
RThe radius of the circle (m)