Функция вычисления длины отрезка

import java.util.Scanner;
 
public class Program1 {
    static Scanner in= new Scanner(System.in);
    public static void main(String[] args) {
        int 
        x1 = in.nextInt(),
        y1 = in.nextInt(),
        x2 = in.nextInt(),
        y2 = in.nextInt(),
        x3 = in.nextInt(),
        y3 = in.nextInt();
       
      
       System.out.printf("%.10f", (len(x1,y1,x2,y2)+len(x1,y1,x3,y3)+len(x2,y2,x3,y3)));
    }
    public static double len(int x, int y, int xk, int yk)
   {
       return(Math.sqrt((x-xk)*(x-xk)+(y-yk)*(y-yk)));
 
   }
}

public class Point {
   
    private double x;
    private double y;
 
    public double getX() {
        return x;
    }
 
    public double getY() {
        return y;
    }
 
    public Point(double x, double y) {
        this.x = x;
        this.y = y;
    }
 
    public double distanceTo(Point point) {
        double temp = Math.pow(point.getX() - x, 2);
        temp += Math.pow(point.getY() - y, 2);
        return Math.sqrt(temp);
    }
}

public class Triangle {
  
    private Point a;
    private Point b;
    private Point c;
 
    public Point getA() {
        return a;
    }
 
    public Point getB() {
        return b;
    }
 
    public Point getC() {
        return c;
    }
 
    public Triangle(Point a, Point b, Point c) {
        this.a = a;
        this.b = b;
        this.c = c;
    }
 
    public double area() {
        double sideA = a.distanceTo(b);
        double sideB = a.distanceTo(c);
        double sideC = b.distanceTo(c);
        double s = (sideA + sideB + sideC) / 2;
        double areaTriangle = Math.sqrt(s * (s - sideA) * (s - sideB) * (s - sideC));
        if (areaTriangle == 0) {
            throw new IllegalArgumentException("The area triangle can't be calculated");
        }
        return areaTriangle;
    }
}

   Triangle figure = new Triangle(new Point(0, 1), new Point(2, 4), new Point(5, 1));
   String result = figure.area();

public static double len(double x, double y, double xk, double yk)

public class TestTriagl {
    public static void main(String[] args) {
        int x1 = -15809;
        int y1 = 20304;
 
        int x2 = 18912;
        int y2 = -10503;
 
        int x3 = 10020;
        int y3 = 22779;
 
        double A = lenSide(x1, y1, x2, y2);
        double B = lenSide(x1, y1, x3, y3);
        double C = lenSide(x2, y2, x3, y3);
 
        System.out.printf("Answer: %.10f", A + B + C);
    }
 
    public static double lenSide(int x1, int y1, int x2, int y2) {
        return Math.sqrt(Math.pow(x1 - x2, 2) + Math.pow(y1 - y2, 2));
    }
}

Answer: 106814,5554724964
Process finished with exit code 0