（Triangle类）设计一个继承了抽象类GeometricObject的新的Triangle类。绘制Triangle类和GeometricObject类的UML图并实现Trian类。编写测试程序，提示用户输入三角形的三条边，颜色以及一个表明该三角形是否填充的布尔值。程序应该使用这些边来创建一个Triangle对象，并根据用户的输入来设置color和filled属性。程序应该显示面积，周长，颜色以及表明是否被填充的真或假的值

## Triangle类和GeometricObject类的UML图

                    GeometricObject
                    -color: String
                    -filled: boolean
                    +GeometricObject()
                    +GeometricObject(color: String, filled: boolean)
                    +getColor(): String
                    +setColor(color: String): void
                    +isFilled(): boolean
                    +setFilled(filled: boolean): void
                    +toString(): String
                    
                            |
                            |
                            |
                            V
                    Triangle
                    -side1: double
                    -side2: double
                    -side3: double
                    +Triangle()
                    +Triangle(side1: double, side2: double, side3: double)
                    +Triangle(side1: double, side2: double, side3: double, color: String, filled: boolean)
                    +getSide1(): double
                    +getSide2(): double
                    +getSide3(): double
                    +getArea(): double
                    +getPerimeter(): double
                    +toString(): String

## Triangle类的实现

public class Triangle extends GeometricObject {
    private double side1;
    private double side2;
    private double side3;

    public Triangle() {
        this.side1 = 1.0;
        this.side2 = 1.0;
        this.side3 = 1.0;
    }

    public Triangle(double side1, double side2, double side3) {
        this.side1 = side1;
        this.side2 = side2;
        this.side3 = side3;
    }

    public Triangle(double side1, double side2, double side3, String color, boolean filled) {
        super(color, filled);
        this.side1 = side1;
        this.side2 = side2;
        this.side3 = side3;
    }

    public double getSide1() {
        return side1;
    }

    public double getSide2() {
        return side2;
    }

    public double getSide3() {
        return side3;
    }

    public double getArea() {
        double s = (this.side1 + this.side2 + this.side3) / 2.0;
        return Math.sqrt(s * (s - this.side1) * (s - this.side2) * (s - this.side3));
    }

    public double getPerimeter() {
        return this.side1 + this.side2 + this.side3;
    }

    public String toString() {
        return "Triangle: side1 = " + this.side1 + " side2 = " + this.side2 +
                " side3 = " + this.side3;
    }
}

## 测试程序

import java.util.Scanner;

public class TestTriangle {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);

        System.out.print("Enter three sides of a triangle: ");
        double side1 = input.nextDouble();
        double side2 = input.nextDouble();
        double side3 = input.nextDouble();

        System.out.print("Enter the color of the triangle: ");
        String color = input.next();

        System.out.print("Is the triangle filled (true / false)? ");
        boolean filled = input.nextBoolean();

        Triangle t1 = new Triangle(side1, side2, side3, color, filled);

        System.out.println("Triangle t1: " + t1.toString());
        System.out.println("Area: " + t1.getArea());
        System.out.println("Perimeter: " + t1.getPerimeter());
        System.out.println("Color: " + t1.getColor());
        System.out.println("Is Filled: " + t1.isFilled());
    }
}