DOI: 10.1063/5.0343594 ISSN: 0034-6748
Solid angle of the off-axis circle sector
Richard J. MatharThe solid angle of a circular sector specified by circle radius, angle of the sector, and distance of the circle plane to the observer is calculated in terms of inverse trigonometric functions and elliptic integrals of the third kind. This generalizes results that have previously appeared in the literature for the full circle.