<P> In geometry, a circular segment (symbol: ⌓) is a region of a circle which is "cut off" from the rest of the circle by a secant or a chord . More formally, a circular segment is a region of two - dimensional space that is bounded by an arc (of less than 180 °) of a circle and by the chord connecting the endpoints of the arc . </P> <P> Let R be the radius of the circle, θ the central angle in radians, α is the central angle in degrees, c the chord length, s the arc length, h the sagitta (height) of the segment, and d the height of the triangular portion . </P>

Arc length of a portion of a circle