The volume of a cube is the product of its dimensions. Since all three dimensions have the same length, we just need to multiply the length of one dimension 3 times.
So if one dimension of the building block is equal 1/12x^2, we have that:
![\begin{gathered} \text{Volume}=d^3 \\ \text{Volume}=((1)/(12)x^2)^3 \\ \text{Volume}=((x^2)^3)/(12^3) \\ \text{Volume}=(x^6)/(1728) \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/e6sosbil9el4j46pgme2dsxjornei2ovj4.png)
So the volume of the building block is equal (1/1728)x^6.