对不对 符合作业题意么

父类

package cxl.lxb;

public abstract class Shape {

public abstract void mianji();

public abstract void zhouchang();

}

子类

package cxl.lxb;

public class Rectangle extends Shape {

@Override

public void mianji() {

// TODO Auto-generated method stub

double sum=40;

System.out.println("矩形面积为"+sum);

}

@Override

public void zhouchang() {

// TODO Auto-generated method stub

int;

System.out.println("矩形周长为"+lang);

}

}

子类

package cxl.lxb;

public class Circle extends Shape {

@Override

public void mianji() {

// TODO Auto-generated method stub

double sum=90;

System.out.println("圆形面积为"+sum);

}

@Override

public void zhouchang() {

// TODO Auto-generated method stub

double;

System.out.println("圆形周长为"+lang);

}

}

入口类

package cxl.lxb;

public class Initail {

/**

* @param args

*/

public static void main(String[] args) {

// TODO Auto-generated method stub

      Shape sha=new Rectangle();

      sha.mianji();

      sha.zhouchang();

      Shape sha1=new Circle();

      sha1.mianji();

      sha1.zhouchang();

}

}