Answer
$x = 8$
$y = 8 \sqrt 2$
Work Step by Step
In a $45^{\circ}-45^{\circ}-90^{\circ}$ triangle, the hypotenuse is $\sqrt 2$ times each leg. Let's write an equation to solve for $y$, the length of the hypotenuse:
$y = \sqrt 2(8)$
Let's rewrite the radical:
$y = 8 \sqrt 2$