Question

If the length of diagonal of a cube is $6\sqrt{3}\mathrm{cm}$, then the length of each edge of the cube is 3 cm.

Answer 1

False.
Let a cm be the side of the cube.
Then we have:

$$\begin{gathered} \sqrt{3}a=6\sqrt{3} \\ \Rightarrow a=6\mathrm{cm} \end{gathered}$$