第八章第三十二题（几何：三角形面积）（triangle area）

第八章第三十二题（几何：三角形面积）（triangle area）

• *8.32（几何：三角形面积）编写一个方法，使用下面的方法头，返回一个三角形的面积：
  public static double getTriangleArea(double[][] points)
  这些点保存在一个4x2的二维数组points中，其中（points[0][0]，points[0][1]）代表（x1，y1）。三角形面积的计算可以使用编程练习题2.19中的公式。如果三个点在一条直线上，方法返回0.编写一个程序，提示用户输入三角形的三个点，然后显示三角形的面积。下面是一个运行示例。
  Enter x1,y1,x2,y2,x3,y3 : 2.5 2 5 -1.0 4.0 2.0
  The area of the triangle is 2.2500000000000013
  Enter x1,y1,x2,y2,x3,y3 : 2 2 4.5 4.5 6 6
  The three points are on the same line
  *8.32（triangle area）Write a method, use the following method header to return the area of a triangle:
  public static double getTriangleArea(double[][] points)
  These points are stored in the two-dimensional array [1 s] [0] in [1 s] [0]. The calculation of triangle area can use the formula in programming exercise 2.19. If three points are on a straight line, the method returns 0. Write a program to prompt the user to input three points of the triangle, and then display the area of the triangle. Here is a running example.
  Enter x1,y1,x2,y2,x3,y3 : 2.5 2 5 -1.0 4.0 2.0
  The area of the triangle is 2.2500000000000013
  Enter x1,y1,x2,y2,x3,y3 : 2 2 4.5 4.5 6 6
  The three points are on the same line

• 参考代码：

  package chapter08;
  
  import java.util.Scanner;
  
  public class Code_32 {
       
      public static void main(String[] args) {
       
          double[][] points = new double[3][2];
          System.out.print("Enter x1,y1,x2,y2,x3,y3 : ");
          Scanner PointsInput = new Scanner(System.in);
          points[0][0] = PointsInput.nextDou