# 2 points on a plane my $x = 2; my $y = 1; #yang is the y-angle 0-360 i want to rotate by my $yang = 45; #convert yang to radians $yang = 3.14159265358979*$yang/180; my $xnew = cos($yang)*$x - sin($yang)*y; my $ynew = sin($yang)*$x + cos($yang)*y; print "x=$xnew, y=$ynew\n";