编辑代码

public class Main {
	public static void main(String[] args) {
       square obj = new square();
       obj.zouchang();
       obj.mainji();
	}
}
class Graphic {

    public void zhouchang(){

    }
    public void mainji(){

    }
}

class Circle extends Graphic {
    int r=10;
    public void zouchang(){
        double zc = 2*3.14*r;
        System.out.println("圆形的周长是:"+zc);
    }
    public void mainji(){
        double mj = 2*3.14*r*r;
        System.out.println("圆形的面积是:"+mj);
    }
}

class square extends Graphic {
    int l=5;
    int h=2;
    public void zouchang(){
        double zc = 2*l+2*h;
        System.out.println("长方形的周长是:"+zc);
    }
    public void mainji(){
        double mj = l*h;
        System.out.println("长方形的面积是:"+mj);
    }
}