What is the length of the side of an equilateral triangle, if its area is $64\sqrt{3}\text{sq cm}$?

The formula for the area of an equilateral triangle with side length $a$ is:
$$\text{Area}=\frac{\sqrt{3}}{4}{a}^2$$
Given that the area is $64\sqrt{3}\text{sq cm}$:
$$\frac{\sqrt{3}}{4}{a}^2=64\sqrt{3}$$
Divide both sides by $\sqrt{3}$:
$$\frac{1}{4}{a}^2=64$$
$$a^2=64\times 4$$
$$a^2=256$$
$$a=\sqrt{256}=16\text{cm}$$
Therefore, the length of the side of the equilateral triangle is $16\text{cm}$.