From a1f7c6130926b697c2df3d158fa2b32870241efa Mon Sep 17 00:00:00 2001
From: Lanyutong <228508663@qq.com>
Date: Thu, 2 Apr 2026 22:06:37 +0800
Subject: [PATCH] =?UTF-8?q?=E5=8F=AA=E6=8F=90=E4=BA=A4=20W4=20=E6=96=87?=
 =?UTF-8?q?=E4=BB=B6=E5=A4=B9?=
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---
 W4/Area.java.txt | 42 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)
 create mode 100644 W4/Area.java.txt

diff --git a/W4/Area.java.txt b/W4/Area.java.txt
new file mode 100644
index 0000000..6537028
--- /dev/null
+++ b/W4/Area.java.txt
@@ -0,0 +1,42 @@
+abstract class Area{
+    public abstract double draw();
+}
+class circle extends Area{
+    double r;
+    public double draw() {
+        double area = 3.14 * r * r;
+        System.out.println(area);
+        return area;
+    }
+}
+class rectangle extends Area{
+    double l,b;
+    public double draw() {
+        double area = l * b;
+        System.out.println(area);
+        return area;
+    }
+}
+class tangle extends Area{
+    double b,h;
+    public double draw() {
+        double area = 0.5 * b * h;
+        System.out.println(area);
+        return area;
+    }
+}
+public class Main{
+    static void main(String[] args) {
+        circle c=new circle();
+        c.r=5;
+        c.draw();
+        rectangle a=new rectangle();
+        a.l=5;
+        a.b=4;
+        a.draw();
+        tangle t=new tangle();
+        t.b=5;
+        t.h=4;
+        t.draw();
+    }
+}
\ No newline at end of file