Answer
YZ = 8
XY= 8$\sqrt 2$
Work Step by Step
By the given Figure
$\angle Z=90^{\circ}$ given
$\angle X = 45^{\circ}$ given
So remaining $\angle Y = 45^{\circ}$
now XZ = 8 given
YZ = 8
XY= 8$\sqrt 2$
By Theorem 5.5.1/ (45-45-90 Theorem)