Step 1: The length \( L \) of each tangent from a point external to a circle can be found using the formula:
\[
L = r \cdot \tan \left(\frac{\theta}{2}\right)
\]
Step 2: Substituting \( r = 3 \, \text{cm} \) and \( \theta = 60^\circ \):
\[
L = 3 \cdot \tan(30^\circ) = 3 \cdot \frac{1}{\sqrt{3}} = \sqrt{3} \times 3 = 3\sqrt{3} \, \text{cm}
\]
Thus, the correct answer is \( \boxed{3\sqrt{3} \, \text{cm}} \).