Encyclopedia > Steradian

  Article Content

Steradian

The steradian (ste from Greek stereos, solid) is the SI supplementary unit of solid angle. The symbol is sr.

It is defined as "the solid angle subtended at the center of a sphere of radius r by a portion of the surface of the sphere having an area r2". It is also equal to the spherical area of a polygon having an angle excess of 1 radian.

There are 4π steradians in a complete sphere.



All Wikipedia text is available under the terms of the GNU Free Documentation License

 
  Search Encyclopedia

Search over one million articles, find something about almost anything!
 
 
  
  Featured Article
French resistance

... and the formation of Vichy France government had begun. De Gaulle also became a de facto leader of Free French Forces. Various groups organized in both occupie ...

 
 
 
This page was created in 43.8 ms