Answer:
8\sqrt{2}\ units.
Explanation:
Use the trignometric property.
sin\theta = \frac{Perpendicular}{Hypotenuse}
Perpendicular = 8
Hypotenuse = h
\theta = 45^{\circ}
sin\ 45^{\circ} = \frac{1}{\sqrt{2}}
\frac{1}{\sqrt{2}} = \frac{8}{h}
h = 8\sqrt{2}\ units
Hope I helped you! x