This isn't right.

You've got a 30/60/90 degree triangle with the side opposite the 30 deg angle, $h=4$.

so by the properties of this triangle the hypotenuse is 8, and the other, $b=4\sqrt{3}$.

The area of a right triangle is $\large \frac{b h}{2}$ and you have 6 of these triangles in your original triangle.

See if you can come up with the correct answer now.