\textbf{128-} In a regular trapezoid, one of the base angles is $60°$ and the base lengths are $6$ and $10$ units. The area of the four triangles formed by the intersection of the internal diagonals of this trapezoid is how much?
\medskip
(1) $8$ \hfill (2) $10$ \hfill (3) $14$ \hfill (4) $16$
\medskip