public class RecclassDemo{
    	double length,width;
	void setLW(double l, double w){
         	length=l;  width=w;
     	}
     	double area(){
         	return length*width;
	}
	public static void main(String args[]){
        	 RecclassDemo r1;                 //Ķ
        	 r1=new RecclassDemo ();           //Ϊռ
        	 r1.setLW(10,20);                  //óԱиֵ
        	 System.out.println("The Rectangle area is :  "+r1.area());    //óԱ
	}
}