Question 203728
If two angles are 120, then the other two must total {{{360-2*120}}} = {{{120}}}
So each other angle is 60.
When you draw diagonals in a rhombus, they form right angles at their intersection. See this URL down near the bottom --> http://www.math-prof.com/Geom/Geom_Ch_22.asp

So, what we have after we draw in the diagonals, is 4 triangles. Each triangle is 30-60-90. And the hypotenuse is 6.

Using the properties of a 30-60-90 (see http://www.themathpage.com/aTrig/30-60-90-triangle.htm), you can get the length of the other two legs. 

Once you have that info, finding the area is easy {{{A = bh/2}}}

Since you have 4 congruent triangles, the total area is 4 times the area of a single triangle