java/w4/Main.java

public class Main {
    public static void main(String[] args) {
        // 创建图形对象
        Shape circle    = new Circle(5.0);
        Shape rectangle = new Rectangle(4.0, 6.0);
        Shape triangle  = new Triangle(3.0, 8.0);

        // 存入数组，统一处理（多态）
        Shape[] shapes = { circle, rectangle, triangle };

        System.out.println("===== 图形面积计算器 =====");
        for (Shape s : shapes) {
            ShapeUtil.printArea(s);
        }

        System.out.println();
        Shape largest = ShapeUtil.findLargest(shapes);
        System.out.println("面积最大的图形是：" + largest.getName()
                           + "（面积 = " + String.format("%.2f", largest.getArea()) + "）");
    }
}