Using the definition of the tangent function, you can find ...
... FA = DF·tan(30°) = (7√3)·(1/√3) = 7
Then the usual formula for triangle area can be used:
... Area = (1/2)bh = (1/2)·(7√3)(7)
... Area = (49/2)√3 square units
... ≈ 42.44 square units