text: The result from the previous example can be used to solve the analogous problem in three dimensions, i.e., scattering from a perfectly reflecting sphere of radius . 
  The plane perpendicular to the incoming light beam can be parameterized by cylindrical coordinates  and . In any plane of the incoming and the reflected ray we can write (from the previous example):
  while the impact area element is
  In spherical coordinates,
  Together with the trigonometric identity
  we obtain
  The total cross section is