Cuboid

The area of three adjacent faces of a cuboid are $x, y$ and $z$ units. If the volume is $V$ cubic units, then prove that $V^2=xyz$

Find the volume, the surface area and the lateral surface area of a cuboid whose length $=8.5 \mathrm{m},$ breadth $=6.4 \mathrm{m}$ and height $=50 \mathrm{cm}$