public class Rectangle {
	int width;
	int height;
	public Rectangle(int w,int h){
		width = w;
		height = h;
	}
	public int getArea(){
		return width*height;
	}
}

public class Square extends Rectangle {
	public Square(int w,int h) {
		super(w,h);
	}
	
	public int getArea(){
		return width*width;
	}
}

public class Test {
	public static void main(String[] args) {
		Rectangle rectangle = new Rectangle(10,20);
                // Square rectangle = new  Square(10,20);
		System.out.println("面积："+rectangle.getArea());
	}
}