Answer
$A = 0.25x^2 \sqrt 3$
Work Step by Step
Area of a Triangle = $0.5bh$ (b = base, h = height)
Using the 30-60-90 triangle, with x being a hypotenuse, the height will be $0.5x\sqrt 3$
Base = x
So $A = 0.5 (x)(0.5x\sqrt 3)$
$A = 0.25x^2 \sqrt 3$
