How to calculate area, perimeter of rectangle or area, circumference of circle in Java

import java.io.*;

public class q2

{

          public static void main(String args[]) throws Exception

          {

                   InputStreamReader in = new InputStreamReader(System.in);

         

                    BufferedReader br = new BufferedReader(in);

         

                    System.out.println("1. area and perimeter of rectangle");

         

                    System.out.println("2. area and circumference of a circle");

         

                    System.out.print("Enter choice : ");

         

                    int ch=Integer.parseInt(br.readLine());

         

                    if(ch==1)

                   {

                             System.out.print("Enter rectangle length : ");

         

                             float length=Float.parseFloat(br.readLine());

         

                             System.out.print("Enter rectangle breath : ");

         

                             float breath=Float.parseFloat(br.readLine());

         

                             float rarea = length*breath;

         

                             float rperimeter = 2*(length+breath);

         

                             System.out.println("Area : "+rarea);

         

                             System.out.println("Perimeter : "+rperimeter);

                   }

                   else

                             if(ch==2)

                             {

                                      System.out.print("Enter circle radius : ");

         

                                       float crad=Float.parseFloat(br.readLine());

         

                                       float carea = 3.14f*crad*crad;

         

                                       float ccir = 2*3.14f*crad;

         

                                       System.out.println("Area : "+carea);

         

                                       System.out.println("Circumference : "+ccir);

                             }

                             else

                                      System.out.println("Wrong Input");

          }

}