import java.util.*;
//抽象类
abstract class Shape 
{
   public abstract Double calculateShape();
}
//Rectangle类
 class Rectangle extends  Shape
 {
    private double length;
    private double width;    
   public Rectangle(double length, double width)
   {
       this.length = length;
       this.width = width;
   }
   public double getLength() 
   {
       return length;
   }public void setLength(double length) 
   {
       this.length = length;
   }
   public double getWidth() 
   {
       return width;
   }public void setWidth(double width)
   {
       this.width = width;
   }
   //继承Shape类，实现getArea()方法
   public Double getArea() 
   {
       return width*length;
   }
}
// Circle类
class Circle extends Shape
{
   private double radius;
  
     public Circle(double radius) 
     {
         this.radius = radius;
     }
     public double getRadius()
     {
         return radius;
     }
     public void setR(double radius) 
     {
         this.radius = radius;
     }
     //继承Shape类，实现getArea()方法
     public Double getArea() 
     {
         return Math.PI*radius*radius;
     }	
 }

 class Main {
     public static void main(String[] args) {
    	 Scanner sc=new Scanner(System.in);
    	 
    	 double radius=sc.nextDouble();
         Circle circle=new Circle(radius);
         System.out.println("半径为:"+circle.getRadius()+"的圆面积为:"+circle.getArea());
         
         double width=sc.nextDouble();
         double length=sc.nextDouble();
         Rectangle rectangle=new Rectangle(width,length);
         
         System.out.println("长为:"+rectangle.getLength()+"宽为:"+rectangle.getArea()+"的长方形面积为:"+rectangle.calculateShape());       
     }
 }

样例运行结果：

END