Calculate Circle Area and Circle Perimeter and Rectangle Area in java

Calculate Circle Area

import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStreamReader;

public class CalculateCircleArea

{

public static void main(String[] args)

{               

int radius = 0;

System.out.println("Please enter radius of a circle");             

try

{

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

radius = Integer.parseInt(br.readLine());

}

catch(NumberFormatException ne)

{

System.out.println("Invalid radius value" + ne);

System.exit(0);

}

catch(IOException ioe)

{

System.out.println("IO Error :" + ioe);

System.exit(0);

}

double area = Math.PI * radius * radius;             

System.out.println("Area of a circle is " + area);

   }

}

Calculate Circle Perimeter

import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStreamReader;

public class CalculateCirclePerimeterExample

{

public static void main(String[] args)

{              

int radius = 0;

System.out.println("Please enter radius of a circle");           

try

{

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

radius = Integer.parseInt(br.readLine());

}

catch(NumberFormatException ne)

{

System.out.println("Invalid radius value" + ne);

System.exit(0);

}

catch(IOException ioe)

{

System.out.println("IO Error :" + ioe);

System.exit(0);

}

double perimeter = 2 * Math.PI * radius;               

System.out.println("Perimeter of a circle is " + perimeter);

}

}

Calculate Rectangle Area

import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStreamReader;

public class CalculateRectArea

          {

public static void main(String[] args)

{               

int width = 0;

int length = 0;                 

try

{

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

System.out.println("Please enter length of a rectangle");

length = Integer.parseInt(br.readLine());

System.out.println("Please enter width of a rectangle");

width = Integer.parseInt(br.readLine());

catch(NumberFormatException ne)

{

System.out.println("Invalid value" + ne);

System.exit(0);

}

catch(IOException ioe)

{

System.out.println("IO Error :" + ioe);

System.exit(0);

}               

int area = length * width;               

System.out.println("Area of a rectangle is " + area);

   }

}