Let R be the radius of the circle, θ is the central angle in radians, α is the central angle in degrees, c the chord length, s the arc length, h the height of the segment, and d the height of the triangular portion.
- The radius is
- The arc length is
- The chord length is
- The height is
- The angle is
Area of Segment = ½ × (θ - sin θ) × r² (when angle is in radians)
Area of Segment = ½ × ( (α × π/180) - sin α) × r² (when angle is in degrees)