// 1/6 * π = 30° 


// sinθ
---------------------------------
1 / 2
0.5
Math.sin(1/6 * Math.PI)
0.49999999999999994


// cosθ
---------------------------------
Math.sqrt(3) / 2
0.8660254037844386
Math.cos(1/6 * Math.PI)
0.8660254037844387


// tanθ
---------------------------------
1 / Math.sqrt(3)
0.5773502691896258
Math.tan(1/6 * Math.PI)
0.5773502691896257