diff --git a/day09/src/com/inmind/abstract07/test/Rectangle.java b/day09/src/com/inmind/abstract07/test/Rectangle.java
index b3aec99..79f7cdd 100644
--- a/day09/src/com/inmind/abstract07/test/Rectangle.java
+++ b/day09/src/com/inmind/abstract07/test/Rectangle.java
@@ -9,6 +9,12 @@ public class Rectangle extends Shape{
         super(chang,kuan,0.0);
     }
 
+    public Rectangle(double bc){
+        //通过父类的构造方法，将长宽存储起来
+//        super(bc,bc,0.0);
+        this(bc, bc);
+    }
+
     @Override
     public double getArea() {
         //长*宽
diff --git a/day09/src/com/inmind/abstract07/test/Square.java b/day09/src/com/inmind/abstract07/test/Square.java
new file mode 100644
index 0000000..8c1150c
--- /dev/null
+++ b/day09/src/com/inmind/abstract07/test/Square.java
@@ -0,0 +1,11 @@
+package com.inmind.abstract07.test;
+
+public class Square extends Rectangle{
+
+    //定义一个正方行，必须要知道边长，
+    public Square(double bc){
+        //调用父类构造时，只需要传递一个参数
+        super(bc);
+    }
+    //直接继承父类的非私有的方法即可
+}
diff --git a/day09/src/com/inmind/abstract07/test/Test08.java b/day09/src/com/inmind/abstract07/test/Test08.java
index 5c6a97a..be1a3b5 100644
--- a/day09/src/com/inmind/abstract07/test/Test08.java
+++ b/day09/src/com/inmind/abstract07/test/Test08.java
@@ -34,5 +34,8 @@ public class Test08 {
 
         //此时如何快速定义出一个正方行的类，还不用自己实现周长和面积的方法，但是能获取周长和面积！！！
         //提示：1.正方形是一个特殊的长方形  2.继承是可以多层继承的
+        Square square = new Square(2);
+        System.out.println(square.getArea());
+        System.out.println(square.getZC());
     }
 }