The triangle \( \triangle XYZ \) formed by intersections of medians with the sides of the medial triangle has area equal to \( \frac{1}{16} \) of the area of triangle \( \triangle ABC \).
\[ \text{Area of } \triangle XYZ = \frac{1}{16} \times \text{Area of } \triangle ABC = \frac{1}{16} \times 1440 = 90 \, \text{cm}^2 \]
For any natural number $k$, let $a_k = 3^k$. The smallest natural number $m$ for which \[ (a_1)^1 \times (a_2)^2 \times \dots \times (a_{20})^{20} \;<\; a_{21} \times a_{22} \times \dots \times a_{20+m} \] is: