参考以下类图提示，完成以下实验任务。 （1）参照类图编写类代码； （2）定义图形抽象类，定义抽象draw方法，并为具体图形类定义具体方法的实 现； （3）设计并定义具体图形面积计算、周长计算方法； （4）编写Test类，测试draw方法。

抽象类：

abstract class Shape {
    public abstract void draw();
    public abstract double calculateArea();
    public abstract double calculatePerimeter();
}

具体类：

class Circle extends Shape {
    private double radius;

    public Circle(double radius) {
        this.radius = radius;
    }

    @Override
    public void draw() {
        System.out.println("Drawing a circle with radius " + radius);
    }

    @Override
    public double calculateArea() {
        return Math.PI * radius * radius;
    }

    @Override
    public double calculatePerimeter() {
        return 2 * Math.PI * radius;
    }
}

class Rectangle extends Shape {
    private double width;
    private double height;

    public Rectangle(double width, double height) {
        this.width = width;
        this.height = height;
    }

    @Override
    public void draw() {
        System.out.println("Drawing a rectangle with width " + width + " and height " + height);
    }

    @Override
    public double calculateArea() {
        return width * height;
    }

    @Override
    public double calculatePerimeter() {
        return 2 * (width + height);
    }
}

class Triangle extends Shape {
    private double a;
    private double b;
    private double c;

    public Triangle(double a, double b, double c) {
        this.a = a;
        this.b = b;
        this.c = c;
    }

    @Override
    public void draw() {
        System.out.println("Drawing a triangle with sides " + a + ", " + b + ", and " + c);
    }

    @Override
    public double calculateArea() {
        double p = (a + b + c) / 2;
        return Math.sqrt(p * (p - a) * (p - b) * (p - c));
    }

    @Override
    public double calculatePerimeter() {
        return a + b + c;
    }
}

测试类：

public class Test {
    public static void main(String[] args) {
        Shape circle = new Circle(5.0);
        circle.draw();
        System.out.println("Area: " + circle.calculateArea());
        System.out.println("Perimeter: " + circle.calculatePerimeter());

        Shape rectangle = new Rectangle(3.0, 4.0);
        rectangle.draw();
        System.out.println("Area: " + rectangle.calculateArea());
        System.out.println("Perimeter: " + rectangle.calculatePerimeter());

        Shape triangle = new Triangle(3.0, 4.0, 5.0);
        triangle.draw();
        System.out.println("Area: " + triangle.calculateArea());
        System.out.println("Perimeter: " + triangle.calculatePerimeter());
    }
}