interface Shape
{
	public final static double PI=3.14159;
	abstract double area();
}
class Circle implements Shape
{
	double radius;
	public Circle(double r)
	{
		radius=r;
	}
	public double area()		//ʵ
	{
		return PI*radius*radius;
	}
}
class Rectangle implements Shape
{
	double width,height;
	public Rectangle(double w,double h)
	{
		width=w;
		height=h;
	}
	public double area()		//ʵ
	{
		return width*height;
	}
}
public class InheritancePolyphormise5_2 
{
	public static void main(String[] args) 
	{
		//ӿڵĶ̬
		Shape s1=new Circle(10);
		Shape s2=new Rectangle(5,5);
		System.out.println("ԲεΪ"+s1.area());
		System.out.println("εΪ"+s2.area());
	}
}
