diff --git a/w4/Circle.java b/w4/Circle.java
new file mode 100644
index 0000000..953ad52
--- /dev/null
+++ b/w4/Circle.java
@@ -0,0 +1,24 @@
+package com.rental.shape;
+
+public class Circle extends Shape {
+    
+    private double radius;
+    
+    public Circle(double radius) {
+        super("圆");
+        this.radius = radius;
+    }
+    
+    public double getRadius() {
+        return radius;
+    }
+    
+    public void setRadius(double radius) {
+        this.radius = radius;
+    }
+    
+    @Override
+    public double getArea() {
+        return Math.PI * radius * radius;
+    }
+}
diff --git a/w4/Main.java b/w4/Main.java
new file mode 100644
index 0000000..2c621b5
--- /dev/null
+++ b/w4/Main.java
@@ -0,0 +1,22 @@
+package com.rental.shape;
+
+public class Main {
+    
+    public static void main(String[] args) {
+        System.out.println("========== 图形面积计算器测试 ==========\n");
+        
+        Circle circle = new Circle(5);
+        System.out.println("--- 圆形测试 ---");
+        ShapeUtil.printArea(circle);
+        
+        Rectangle rectangle = new Rectangle(4, 6);
+        System.out.println("--- 矩形测试 ---");
+        ShapeUtil.printArea(rectangle);
+        
+        Triangle triangle = new Triangle(8, 5);
+        System.out.println("--- 三角形测试 ---");
+        ShapeUtil.printArea(triangle);
+        
+        System.out.println("========== 测试完成 ==========");
+    }
+}
diff --git a/w4/Rectangle.java b/w4/Rectangle.java
new file mode 100644
index 0000000..71f754f
--- /dev/null
+++ b/w4/Rectangle.java
@@ -0,0 +1,34 @@
+package com.rental.shape;
+
+public class Rectangle extends Shape {
+    
+    private double width;
+    private double height;
+    
+    public Rectangle(double width, double height) {
+        super("矩形");
+        this.width = width;
+        this.height = height;
+    }
+    
+    public double getWidth() {
+        return width;
+    }
+    
+    public void setWidth(double width) {
+        this.width = width;
+    }
+    
+    public double getHeight() {
+        return height;
+    }
+    
+    public void setHeight(double height) {
+        this.height = height;
+    }
+    
+    @Override
+    public double getArea() {
+        return width * height;
+    }
+}
diff --git a/w4/Shape.java b/w4/Shape.java
new file mode 100644
index 0000000..cfb8fdb
--- /dev/null
+++ b/w4/Shape.java
@@ -0,0 +1,16 @@
+package com.rental.shape;
+
+public abstract class Shape {
+    
+    private String name;
+    
+    public Shape(String name) {
+        this.name = name;
+    }
+    
+    public String getName() {
+        return name;
+    }
+    
+    public abstract double getArea();
+}
diff --git a/w4/ShapeUtil.java b/w4/ShapeUtil.java
new file mode 100644
index 0000000..b16fff5
--- /dev/null
+++ b/w4/ShapeUtil.java
@@ -0,0 +1,10 @@
+package com.rental.shape;
+
+public class ShapeUtil {
+    
+    public static void printArea(Shape shape) {
+        System.out.println("图形名称: " + shape.getName());
+        System.out.println("面积: " + shape.getArea());
+        System.out.println("----------------------");
+    }
+}