x=16, y= [tex] \sqrt{2} [/tex]
you can extend down a vertical line, so you know that portion of x is 7, and that side of the triangle is 9, since 45-90-45 triangles have 2 legs of equal length.
then you know the other leg of the triangle is 9, and adding 9+7 x=16. to find y you can know that 45-90-45 triangles have sides in a [tex]1:1:\sqrt{2}[/tex] ratio, so this triangle is [tex]9:9:9\sqrt{2}[/tex]