UNITS A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z                    HOME ABOUT CATEGORIES SITE MAP COPYRIGHT ADVERTISE CONTACT entire Web this site steradian (sr) One of two supplementary (dimensionless) units in the SI system of units (the other being the radian). The steradian is a unit of solid angle. It is defined as the solid central angle of a sphere which encloses a surface on the sphere equal to the square of the sphere's radius. Related category    • UNITS Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History Transport Concepts & Designs (partner site) BACK TO TOP