The sides of a trapezoid are 5, 8, 11, and 13, and its diagonals are also integer numbers; what are they?
(In reply to
Solution, by hand by Old Original Oskar!)
After reading your post, I went back to my program and found a trivial bug (forgot an ! in front of an =). Upon fixing it, my program generated the answer your found.
Just for your information, my program does not perform any rounding - you can go to my original post to see exactly how it works.