steradian

• Substantivo que designa a unidade de medida de ângulo sólido no Sistema Internacional (SI), definida como o ângulo sólido que, tendo o vértice no centro de uma esfera, recorta na superfície dessa esfera uma área igual ao quadrado do raio.

A noun referring to the SI unit of solid angle, defined as the solid angle subtended at the center of a sphere by an area on its surface equal to the square of the sphere's radius.

1. C2formalscientific

   The SI unit of solid angle, equal to the solid angle subtended at the center of a sphere by an area on its surface equal to the square of the sphere's radius.

   Unidade de ângulo sólido

   • The total solid angle of a sphere is 4π steradians.
   • The intensity of the light source was measured in lumens per steradian.
   • A full sphere contains approximately 12.57 steradians.