How do you find the length width and height of a cuboid if you know the area of each face?

You know LW, WH and HL

Multiply all three together to give L2W2H2

Then take the principal square root = LWH

Now

Divide LWH by LW. That gives H.

Divide LWH by WH. That gives L.

Divide LWH by HL. That gives W.