Question

我试图创建一个程序，在该程序中创建一个圆圈中的三个随机点，并导致创建一个内切三角形。然而，我得到的角度都搞砸了

这是我的代码：

    public static void main(String[] args) {
        double r = 40.0;
        double angle1 = Math.random()* (2 * Math.PI);
        double angle2 = Math.random()* (2 * Math.PI);
        double angle3 = Math.random()* (2 * Math.PI);
        double x_1 = r * Math.cos(angle1); 
        double y_1 = r * Math.sin(angle1);
        double x_2 = r * Math.cos(angle2); 
        double y_2 = r * Math.sin(angle2);
        double x_3 = r * Math.cos(angle3); 
        double y_3 = r * Math.sin(angle3);
        System.out.println("The coordinates of the three points are: 
        (" + x_1 +                 ", " + y_1 + ") 
        (" + x_2 + ", " + y_2 + ") 
        (" + x_3 + ", " + y_3 + ")");
    //Get length of each side
    double distanceFrom1To2 = Math.sqrt(Math.pow(x_2 - x_1, 2) + 
    Math.pow(y_2 - y_1, 2));
    double distanceFrom2To3 = Math.sqrt(Math.pow(x_3 - x_2, 2) + 
    Math.pow(y_3 - y_2, 2));
    double distanceFrom3To1 = Math.sqrt(Math.pow(x_1 - x_3, 2) + 
    Math.pow(y_1 - y_3, 2));
    //Get angles ***
    double triangleAngle1 = Math.atan(distanceFrom1To2 / distanceFrom2To3);
    double triangleAngle2 = Math.atan(distanceFrom2To3 / distanceFrom3To1);
    double triangleAngle3 = Math.atan(distanceFrom3To1 / distanceFrom1To2);
    System.out.println("The three angles are " + triangleAngle1 + " " + 
    triangleAngle2 + " " + triangleAngle3);
    System.out.println(triangleAngle1 + triangleAngle2 + triangleAngle3);
}

我绝对知道获得角度的方法搞砸了。以下是我的程序示例：

    The coordinates of the three points are: (5.224534224725408,  
    -39.65733528787168) (-29.696946087404676, 26.79722733944279) 
    (32.70889681040468, -23.02451018906371)

    The three angles are 0.7545364726122026 1.18830825410364 
    0.40435068059871415
    Total angle sum: 2.347195407314557

所有角度加起来都大于Pi / 2弧度。我已经考虑了正弦定律，但你必须至少知道一个角度......

Answer 1

想出来

这是固定代码：

function runGetList(filename) {
    var p = new Promise(function(resolve, reject) {
        // do stuff to get jsonMDBList
        resolve(jsonMDBList)
    }};
    return p;
}

function getAllLists() {
    var mdbListAll = runGetList('GetListMDBs.py'); // returns promise 1
    mdbListAll.then(function(data) {               // runs when promise 1 resolves
        console.log("list mdbs: " + data);
        mdbListTbl = runGetList('GetTable.py');    // returns promise 2
        return mdbListTbl
    }).then(function(data) {                       // runs when promise 2 resolves
        console.log("table mdbs: " + data);
    });
}

我改变它以使用余弦定律。

圆圈上的三个随机点

1 个答案: