编写 程序，提示用户输入三角形的三个点 (x1,y1) , (x2,y2) , (x3,y3) ,然后显示它的面积。
import java.util.Scanner;public class Home04 {public static void main(String[] args) {Scanner scanner = new Scanner(System.in);System.out.println("请输入点1的坐标：");double x1 = scanner.nextDouble();double y1 = scanner.nextDouble();System.out.println("请输入点2的坐标：");double x2 = scanner.nextDouble();double y2 = scanner.nextDouble();System.out.println("请输入点3的坐标：");double x3 = scanner.nextDouble();double y3 = scanner.nextDouble();/* * 已知A（x1,y1）,B（x2,y2）那么AB之间的距离为√[(X1－X2)^2+(Y1－Y2)^2] * *//* * 点1至点2的距离 * 求根的方法：Math.sqrt(double s); * */double first = Math.sqrt((x1-x2)*(x1-x2)+(cxdxy)*(cxdxy)); /* * 点2至点3的距离 * */double second = Math.sqrt((x2-x3)*(x2-x3)+(y2-y3)*(y2-y3));/* * 点3至点1的距离 * */double third = Math.sqrt((x3-x1)*(x3-x1)+(y3-y1)*(y3-y1)); /* * 计算三角形面积 * */double s = (first+second+third)/2;double area = Math.sqrt(s*(s-first)*(s-second)*(s-third));System.out.println("area"+area);}}