Design a Triangle class that extends the attached Shape class. Run the attached TestTriangle.java to test your Triangle class. You may not change attached Shape.java and TestTriangle.java. Submit chapter13.Triangle.java and TestTriangle.png.

Shape.java:

TestTriangle.java:

package chapter13; import java.lang.String; import java.util.Date; import java.lang.Object; public abstract class Shape extends Object { private final Date dateCreated = new Date(); protected Shape() { super(); public Date getDateCreated () { return this.dateCreated; @Override ublic String toString() { return "created on " + this.getDateCreated(); public abstract double getArea(); public abstract double getPerimeter(); import java.lang. System; import java.lang. String; import java.lang.Math; import chapter13. Triangle; public class TestTriangle { public static void main(String[] args) { if (TestTriangle.isValid(1.0, 1.0, 1.0)) { Triangle triangle1 = new Triangle(1.0, 1.0, 1.0); TestTriangle.displayTriangle(triangle1); } else { System.out.println("invalide sides: 1.0, 1.0, 1.0); System.out.println("Number of triangles: " + Triangle.getNumbe.cofobjects()); System.out.println(); if (TestTriangle.isValid(1.0, 1.0, 2.0)) { Triangle triangle2 = new Triangle(1.0, 1.0, 2.0); TestTriangle.displayTriangle(triangle2); } else { System.out.println("Ivalide sides: 1.0, 1.0, 2.0"); System.out.println("Number of triangles: " + Triangle.getNumberofobjects(); System.out.println(); if (Test Triangle.isValid(5.0, 4.0, 3.0)) { Triangle triangle3 = new Triangle(5.0, 4.0, 3.0); TestTriangle.displayTriangle(triangle3); } else { System.out.println("invalide sides: 5.0, 4.0, 3.0"); System.out.println("Number of triangles: " + Triangle.getNumberOfObjects()); System.out.println(); public static boolean isValid(double sidel, double side2, double side3) { return (side1 + side2 > side3) && (side1 + side3 > side2) && (side2 + side3 > side 1); public static void displayIsEquilateralTriangle(Triangle triangle) { if (triangle. isEquilateral triangle()) { System.out.println("It is an equilateral triangle."); } else { System.out.println("It is not an equilateral triangle."); public static void displayIsRightAngledTriangle(Triangle triangle) { if (triangle.isRightAngledt.ciangle() { System.out.println("It is a right-angled triangle."); } else { System.out.println("It is not a right-angled triangle."); public static void displayTriangle(Triangle triangle) { System.out.println(triangle); System.out.println("Area: " + TestTriangle.roundoff(triangle.getArea()); System.out.println("Perimeter: " + triangle.getPerimeter(); TestTriangle.displayIsEquilateralTriangle(triangle); TestTriangle.displayIsRightAngledTriangle(triangle); public static double roundoff(double d) { return Math.round(d * 100.0) / 100.0