The side on the front of 30° is 1/2 of hypytenuse Then 1/2 of 4=2 and the ather side with theorem of pytagore is squares root of(4^2-2^2)=sq .root of 12 This side(square root of 12) is 1/2 of hypotenuse then Hypotenuse is 2*square root 12 X^2=(2*sq .root12)^2 -(square root 12)^2 X^2=48-12=36 X=6