From 2b616b1f2dcb19398e61e01a3f5b7d4212e28c72 Mon Sep 17 00:00:00 2001
From: pangyaxuan <wuhua.654321@qq.com>
Date: Sun, 29 Mar 2026 22:46:04 +0800
Subject: [PATCH] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=20'W4'?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 W4 | 57 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)
 create mode 100644 W4

diff --git a/W4 b/W4
new file mode 100644
index 0000000..9c8a8c2
--- /dev/null
+++ b/W4
@@ -0,0 +1,57 @@
+// 抽象图形类
+abstract class Shape {
+    public abstract double getArea();
+}
+
+// 圆形
+class Circle extends Shape {
+    private double r;
+
+    public Circle(double r) {
+        this.r = r;
+    }
+
+    @Override
+    public double getArea() {
+        return Math.PI * r * r;
+    }
+}
+
+// 矩形
+class Rectangle extends Shape {
+    private double width;
+    private double height;
+
+    public Rectangle(double width, double height) {
+        this.width = width;
+        this.height = height;
+    }
+
+    @Override
+    public double getArea() {
+        return width * height;
+    }
+}
+
+// 三角形
+class Triangle extends Shape {
+    private double base;
+    private double height;
+
+    public Triangle(double base, double height) {
+        this.base = base;
+        this.height = height;
+    }
+
+    @Override
+    public double getArea() {
+        return 0.5 * base * height;
+    }
+}
+
+// 工具类
+class ShapeUtil {
+    public static void printArea(Shape shape) {
+        System.out.println("面积：" + shape.getArea());
+    }
+}