2020.8.11

学习内容：

 1、线段类

 1 import java.lang.Math;
 2 public class Line1 {
 3     private Point1 p1=new Point1();
 4     private Point1 p2=new Point1();
 5     public void Input() {
 6         System.out.println("请输入线段的起点和终点坐标:");
 7         p1.Input();
 8         p2.Input();
 9     }
10     public void display() {
11         double d;
12         d=Math.sqrt((p1.getX()-p2.getX())*(p1.getX()-p2.getX())+(p1.getY()-p2.getY())*(p1.getY()-p2.getY())+(p1.getZ()-p2.getZ())*(p1.getZ()-p2.getZ()));
13         System.out.printf("线段的长度为:%-9.4f",d);
14     }
15 
16     public static void main(String[] args) {
17         Line1 l=new Line1();
18         l.Input();
19         l.display();
20     }
21 }