public class test {

public static void main(String[] args) {

System.out.println("请输入矩形的长和宽"); 

Shape rec=new Rectangle();

rec.perimeter(); 

rec.area(); 

System.out.println("请输入圆的半径"); 

Shape cir=new Circle(); 

cir.perimeter();

cir.area(); 

}

}