Which of these is a solution to x2+y2=2z2x^2 + y^2 = 2z^2x2+y2=2z2?
(1,1,1)(1, 1, 1)(1,1,1)
(3,1,5)(3, 1, \sqrt{5})(3,1,5)
(7,1,5)(7, 1, 5)(7,1,5)
(1,7,5)(1, 7, 5)(1,7,5)