public abstract class  shape{

   public abstract double  C();

   public abstract double  S();}

public class Rectaugle extends shape {

  double a=4.5;

  double b=2.1;

   double   c=(a+b)*2;

  double  s=a*b;

 public double C (){

System.out.println("矩形周长为"+c);

  return c;}

public double S(){

System.out.println("面积为"+s);

  return s;}

   }

public class Circle extends shape  {

  final double p=3.14;

  double r=2.1;

  double  c=2*p*r;

  double    s=p*r*r;

  public double C(){

  return c;

 System.out.println("圆形周长为"+c);}

 public double S(){

System.out.println("面积为"+s);

 return s;}

}

public class Hello{

 public static void main (String [] args){

 shape s1=new Rectaugle();

 shape s2=new Circle();

 s1.C();

 s1.S();

 s2.C();

 s2.S();}

}