创建Point类和Triangle类求三角形面积和周长（java）

import java.util.Scanner;

class Point
{
    double i;
    double j;
    public Point(double  x,double y)//初始化某个点
    {
        i = x;
        j = y;
    }
    public double distance(Point p)//计算当前点到令一点的距离
    {
        return  Math.sqrt((p.i - this.i)*(p.i - this.i)+(p.j - this.j)*(p.j - this.j));
    }
}

class Triangle
{
    Point d;
    Point e;
    Point f;
    public Triangle(Point a,Point b,Point c)
    {
        d = a;
        e = b;
        f = c;
    }

    public double GetPerimeter()
    {
        return d.distance(e)+e.distance(f)+f.distance(d);
    }

    public double GetArea()
    {

        double p=0.5* (d.distance(e)+e.distance(f)+f.distance(d));
        double b = p-d.distance(e);
        double c = p-e.distance(f);
        double g = p-f.distance(d);
        double area1 = Math.sqrt(p*b*c*g);
       
        return area1;
    }
}

public class Text {

    public static void main(String[] args)
    {
        Scanner sc = new Scanner(System.in);
        System.out.print("请输入三角形第一个点的x坐标值：");
        int x = sc.nextInt();
        System.out.print("请输入三角形第一个点的y坐标值：");
        int y = sc.nextInt();
        System.out.print("请输入三角形第二个点的x坐标值：");
        int p = sc.nextInt();
        System.out.print("请输入三角形第二个点的y坐标值：");
        int q = sc.nextInt();
        System.out.print("请输入三角形第三个点的x坐标值：");
        int m = sc.nextInt();
        System.out.print("请输入三角形第三个点的y坐标值：");
        int n = sc.nextInt();
        Point a = new Point(x,y);
        Point b = new Point(p,q);
        Point c = new Point(m,n);
        Triangle t = new Triangle(a,b,c);
        double l =  t.GetPerimeter();
        System.out.printf("该三角形的周长是：%fn",l);
        double area = t.GetArea();
        System.out.printf("该三角形的面积是：%fn",area);

    }
}