#!/usr/bin/perl

use Math::Trig qw(tan sec csc cot asin acos atan asec acsc acot sinh cosh tanh sech csch coth asinh acosh atanh asech acsch acoth);

sub RadToDegree()
    {
    return (($_[0] * 180)/ Math::Trig->pi());    
    }

.................ca 1000 zeilen code..................

my $beta_Angle_Rad = acos(-0.880251132856693);
my $beta_Angle_Deg = &RadToDegree($beta_Angle_Rad);

print "$beta_Angle_Rad\n";
print "$beta_Angle_Deg";