Answer:
144√3 units^2 ≈ 249.42 units^2
Explanation:
For an n-sided regular polygon with apothem "a", the area is ...
... A = n·a^2·tan(180°/n)
For your 3-sided regular polygon with apothem 4√3, the area is ...
... A = 3·(4√3)^2·tan(60°) = 144√3 . . . units^2