Function sqdegToSteradians( sqdeg )

Description:
Converts a solid angle from square degrees to steradians.

The unit sphere is 4*PI steradians = 360*360/PI square degrees.

Parameters:
sqdeg (floating point)
quantity in square degrees
Return Value (floating point):
quantity in steradians
Example:
round(sqdegToSteradians(41253)/PI) = 4
Signature:
double sqdegToSteradians(double)