My solution resulted in Crash {FLT_INVALID_OPERATION} several times, before I understood, that the square of an integer number can be negative!

Oh! What a stupid mistake!-)

The crash mentioned above was caused by the following function in my source code:

function Dist( const p1, p2: Point ): extended;
begin
    Result := sqrt( sqr(p2.x-p1.x) + sqr(p2.y-p1.y) );
end;

I couldn't even imagine, that sqr() function can produce negative results!

So, If you get Crash on test #6, just use extended (^:

Holy crap
I can't believe either!!
Thanks