设计一个名为triangle的类来扩展geometricobject类，该类包括

1. 三个名为side1,side2,side3的double数据域表示这个三角形的三条边，它们的默认值是1.0
2. 一个无参构造方法创建默认三角形
3. 一个能创建带指定size的三角形构造方法
4. 所有三个数据域的访问器

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java语言程序设计11.1

import java.util.*;
public class eleven111 {
    public static void main(String[] args) {
        double side1,side2,side3;
        boolean filled;

        Scanner input=new Scanner(System.in);

        System.out.println("enter the side1,side2,side3: ");
        side1=input.nextDouble();
        side2=input.nextDouble();
        side3=input.nextDouble();
        triangle a=new triangle(side1,side2,side3);
        System.out.println("is filled?");
        filled=input.nextBoolean();


        if(a.setfilled(filled)==true) {
            input.nextLine();
            System.out.println("set the color: ");
            String color =input.nextLine();
            a.setcolor(color);
        }

    System.out.println(a.toString()+" \n"+a.getarea()+"\n"+a.getmeter()+
            "\n"+a.setfilled(filled)+"\n"+a.color);
    }

}
class triangle extends eleven111{
    private double side1=1.0,side2=1.0,side3=1.0;
    String color;
    public triangle() {

    }
    public triangle(double side1,double side2,double side3) {
        this.side1=side1;
        this.side2=side2;
        this.side3=side3;
    }
    public double side1() {
        return this.side1;
    }
    public double side2() {
        return this.side2;
    }
    public double side3() {
        return this.side3;
    }
    public double getarea() {
        double s=(side1+side2+side3)*1.0/2;
        double area=Math.sqrt(s*(s-side1)*(s-side2)*(s-side3));
        return area;
    }
    public double getmeter() {
        return (side1+side2+side3);
    }
    public String toString() {
        return "Triangle: side1="+side1+" side2= "+side2+" side3= "+side3;
    }
    public boolean setfilled(boolean filled) {
        return filled;
    }
    public void setcolor(String color) {
        this.color=color;
    }
}