//6.5ӿչ
interface Shape
{
	double pi=3.14;
	void setColor(String str);
}
interface Shape2D extends Shape
{
	double getArea();	
}
class Box implements Shape2D          
{
		double r,h;String c;
		public Box(double r,double h)
		{
			this.r=r;
			this.h=h;
		}
		public double getArea()         //ʵֽӿڵĳ󷽷
		{
			return (pi*r*r);
		}
		public void setColor(String c)  //ʵָӿڵĳ󷽷
		{
			this.c=c;
		}
		public static void main(String args[])
		{
			Box box=new Box(2.0,5.0);
			System.out.println("úʽɫΪ"+box.c);
			System.out.println("\núʽݻΪ"+box.h*box.getArea());
				
		}
		
}
