var rng = (a,b)=>Math.random()*(b-a) + a;
var rndPoint = function(r) {
    var a = rng(0, Math.PI * 2);
    return {x : Math.cos(a) * r, y : Math.sin(a) * r};
}
var testInbound = function(a,b,c) {
    var x = (a.x - 0) * (b.y - a.y) - (b.x - a.x) * (a.y - 0);
    var y = (b.x - 0) * (c.y - b.y) - (c.x - b.x) * (b.y - 0);
    var z = (c.x - 0) * (a.y - c.y) - (a.x - c.x) * (c.y - 0);
    if ((x > 0 && y > 0 && z > 0) || (x < 0 && y < 0 && z < 0)) return true;
    return false;
}
var roundTest = function(radius, cnt) {
    var hit = 0;
    for (let i = cnt; i--;) {
        var a = rndPoint(radius), b = rndPoint(radius), c = rndPoint(radius);
        hit += testInbound(a, b, c);
    }
    return hit;
}
var cnt = 10**6
var total = roundTest(100, cnt);
console.log(total);