Persegi

import java.io.*;

public class persegi {

public static void main(String[] args) {

BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

          

           String strsisi = null;         

          

           try {

                System.out.println("Rumus L persegi = sisi x sisi");

                System.out.println("Rumus Lkll persegi = 4 x sisi");

                System.out.print("Masukan sisi (S) : ");

                strsisi=br.readLine();

                    

           }catch (IOException ioe) {

                System.out.println(" Keslahan pada sistem IO");

                System.exit(0);

           }

          

           double sisi;

           double luas;

           double kll;

                sisi =Double.parseDouble(strsisi);

               

               

                luas = sisi * sisi   ;

                System.out.println ("Luas persegi " + luas );

               

                kll = 4 * sisi;

                System.out.println ("Keliling persegi " + kll );

     }

}