老师看一下符不符合题目要求，提点意见

public abstract class Shape {
   public abstract double area();
}
class Rectangle extends Shape {
   private double length;
   private double wide;

   public Rectangle(double length,double wide){
       this.length = length;
       this.wide = wide;
   }
   public double getLength() {
       return length;
   }

   public void setLength(double length) {
       this.length = length;
   }

   public double getWide() {
       return wide;
   }

   public void setWide(double wide) {
       this.wide = wide;
   }

   @Override
   public double area() {
       return wide*length;
   }

   //属性：矩形的长lenghth、宽wide

   //创建带参构造方法以及无参构造方法

   //创建针对长、宽的赋值和取值方法

   //重写父类的area（）方法
}
class Circle extends Shape {
   private double r;
   public Circle(double r){
       this.r = r;
   }

   public double getR() {
       return r;
   }

   public void setR(double r) {
       this.r = r;
   }

   @Override
   public double area() {
       return 3.14*r*r;
   }
 
}

public class Test {
   public static void main(String[] args) {
       //创建类的实例，并分别对圆的半径和矩形的长宽进行赋值
       Rectangle rectangle = new Rectangle(6.0,5.0);
       System.out.println("矩形面积为"+rectangle.area());
       //调用area（）方法，输出结果
       Circle circle = new Circle(6.0);
       System.out.println("圆的面积为"+circle.area());
   }
}