java实现三角形面积和周长的计算

3．先创建一个Point类，然后定义Trianglele类。在Trianglele类中定义三个Point的实体来表示一个三角形的三个点，再定义一个方法setTri对这三个点进行初始化，然后定义两个方法求三角形的周长、面积。在main()中创建一个对象，求给定三点的三角形的周长、面积。3．将上题的方法setTri改用构造方法实现初始化。

主类：Trianglele

属性：Piont point

Int side

方法：Trianglete(point1,point2,point3);

girth(trianglete);

Area(tiranglete);

类名：point

属性：int xcoord

int ycoord

方法：Point(x,y)

package Three;

import java.util.Scanner;

public class Trianglele {

Point point1,point2,point3;

double side1;

double side2;

double side3;

public Trianglele(Point point1,Point point2,Point point3){

//利用构造函数创建一个

三角形，并求出边长

this.point1=point1;

this.point2=point2;

this.point3=point3;

double sidex=point1.pointLen(point2, point3);

this.side1=sidex;

double sidey=point2.pointLen(point1, point3);

this.side2=sidey;

double sidez=point3.pointLen(point1, point2);

this.side3=sidez;

}

/**下面来求周长和面积

* @param args

*/

public double area(){ //求面积

double x1,x2,y1,y2;

double heigth,area;

double sidemax,sidemin1,sidemin2;

if(side1>side2){

sidemax=side1;

x1=point1.xpoint;

y1=point1.ypoint;

x2=(point3.xpoint+point2.xpoint)*0.5;

y2=(point3.ypoint+point2.ypoint)*0.5;

sidemin1=side2;

}else{

sidemax=side2;

sidemin1=side2;

x1=point2.xpoint;

y1=point2.ypoint;

x2=(point3.xpoint+point1.xpoint)*0.5;

y2=(point3.ypoint+point1.ypoint)*0.5;

}

if(sidemax

sidemin2=sidemax;

sidemax=side3;

x1=point3.xpoint;

y1=point3.ypoint;

x2=(point1.xpoint+point2.xpoint)*0.5;

y2=(point1.ypoint+point2.ypoint)*0.5;

}else{

sidemin2=side3;

}

if(sidemax*sidemax==sidemin1*sidemin1+sidemin2*sidemin2){ area=sidemin1*sidemin2*0.5;

}

else{

Point point=new Point(x1,y1);

Point po=new Point(x2,y2);

heigth=point.pointLen(point,po);

area=sidemax*heigth*0.5;

}

return area;

}

public double girth(){

double girth;

girth=side1+side2+side3;

return girth;

}

public static void main(String[] args) {

// TODO Auto-generated method stub

boolean TF=false;

while(TF==false){

System.out.println("请输入你想要的三角形的三个坐标");

Scanner s=new Scanner(System.in);

Double x1=s.nextDouble();

Double y1=s.nextDouble();

Double x2=s.nextDouble();

Double y2=s.nextDouble();

Double x3=s.nextDouble();

Double y3=s.nextDouble();

Trianglele tri=new Trianglele(new Point(x1,y1),new Point(x2,y2),new Point(x3,y3));

if((tri.side1

{ double area=tri.area();

double gir=tri.girth();

System.out.println("这个三角形的面积为："+area+"这个三角形的周长为

"+gir+" "+"程序到此结束!!");

TF=true;}

else{

TF=false;

System.out.println("你所输入的三角形错误");

}

}

}

}

package Three;

import ng.Math;

class Point {

double xpoint;

double ypoint;

public Point(double x,double y){

xpoint=x;

ypoint=y;

}

public double pointLen(Point po1,Point po2){ //求两个点之间的距离double length;

double

len=((po1.xpoint-po2.xpoint)*(po1.xpoint-po2.xpoint)+(po1.ypoint-po2. ypoint)*(po1.ypoint-po2.ypoint));

length=Math.sqrt(len);

return length;