Sin of an angle = opposite side / hypotenuse
sin(30) = square root of (x/2) / 4x
1/2 = square root of (x/2) / 4x
1/2 = square root of ((x/2)/16x^2)
1/2 = square root of (1/32x) / ^2
1/4 = 1/32x / *32x
8x = 1
x = 1/8