苍鹭的公式在Java中使用,但错误的值

Question

编辑//我可能认为Programmr.com用于检查答案输出与预期输出的代码是错误的.因为这里的所有答案都具有几乎相同的公式,并且维基页面上关于英雄公式的公式与此处的答案相同.

在本练习中,完成"返回值"的功能.当你调用这个函数时,它应该使用Heron的公式计算三角形的面积并返回它.

苍鹭的公式:面积=(s*(sa)(sb)(sc))0.5其中s =(a + b + c)/ 2

我写了这个,但似乎不正确,我无法弄清楚出了什么问题.输出结果给出了错误的值:

public class Challenge
{
    public static void main( String[] args )
    {
        double a;

        a = triangleArea(3, 3, 3);
        System.out.println("A triangle with sides 3,3,3 has an area of:" + a);

        a = triangleArea(3, 4, 5);
        System.out.println("A triangle with sides 3,4,5 has an area of:" + a);

        a = triangleArea(9, 9, 9); // ! also realize the 9,9,9 is not even the same as the comment bellow. This was generated by the Programmr.com exercise.  
        System.out.println("A triangle with sides 7,8,9 has an area of:" + a );

    }
    public static double triangleArea( int a, int b, int c )
    {
    double s = (a + b + c)/2;
    double x = ((s) * (s-a) * (s-b) * (s-c));
    double Area = Math.sqrt(x);
    return Area;
}
}



Expected Output
3.897114317029974
6.0
35.074028853269766

Your code's output
2.0
6.0
28.844410203711913

Answer 1

使用这个..苍鹭的形式

double s = (a + b + c)/2.0d;
double x = (s * (s-a) * (s-b) * (s-c));
double Area= Math.sqrt(x);
return Area;