This isn't as difficult as it seems.....the area of the larger square can be found by applying the Law of Cosines directly.to one of the non-equilateral triangles ........
Letting s be the side of the larger square....we have
s^2 = 1^2 + 1^2 - 2(1)(1)cos(150) = [2 + √3 ] ≈ 3.732 units^2
But...since s^2 is the area of the larger square.....this just kind of "falls out".......
Hope that helps.....
