Your answer would be 2 mm. The formula for volume is v=lwh
You have the volume: 4mm. And you have the height: 1. Substituting the known values you have 4=(1)(x)(x).
Now the question is, 1 times what 2 numbers gives you 4? Well 2 does.
4=(1)(2)(2)
The rest of the numbers don't work. 1 times 1 times 1 is 1. 1 times 3 times 3 is 9. And one times 4 times 4 is 16.
