Question

Create a program that uses a Java method to determine the length of a line by inputting the X,Y coordinates of the line endpoints. Show the result with a precision of four decimal places.

Answer 1

Answer:

import java.lang.Math;

import java.util.Scanner;

class lineLength {

 private double x1;

 private double x2;

 private double y1;

 private double y2;

 public lineLength(double x1, double y1, double x2, double y2){

   this.x1 = x1;

   this.x2 = x2;

   this.y1 = y1;

   this.y2 = y2;

   

 }

 public String toString(){

   double length = Math.sqrt( ( ( this.x2 - this.x1 ) * ( this.x2 - this.x1 ) ) + ( ( this.y2 - this.y1 ) * ( this.y2 - this.y1 ) ) );

   String answer = String.format("%.4f %n", length);

   return answer;

 }

}

class Main{

 public static void main(String[] args) {

   Scanner scanner = new Scanner(System.in);

   System.out.println("Please input x1, y1, x2, and y2");

   double x1 = scanner.nextDouble();

   double y1 = scanner.nextDouble();

   double x2 = scanner.nextDouble();

   double y2 = scanner.nextDouble();

   lineLength test = new lineLength(x1,y1,x2,y2);

   System.out.println(test);

 }

}

Explanation:

we use formula

$\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}$