implement triangle method

src/CourseRegistrationStarter/Main.java

@@ -1,15 +1,40 @@
 package CourseRegistrationStarter;
 
-public class Main {
+public class Main
+{
     public static void main(String[] args)
     {
-        // TODO:
         // 1. Create at least 3 courses
+        Course c1 = new Course("Advanced Programming", "CS101", 2);
+        Course c2 = new Course("Mathematics", "MATH201", 1);
+        Course c3 = new Course("Foundations of Mathematical Sciences","MATH301", 3);
+
         // 2. Create 1 student
+        Student s1 = new Student("Romina", "40123456");
+
         // 3. Create a registration system
+        RegistrationSystem regSys = new RegistrationSystem();
+
         // 4. Add courses to the system
+        regSys.addCourseToSystem(c1);
+        regSys.addCourseToSystem(c2);
+        regSys.addCourseToSystem(c3);
+
+        regSys.showAllCourses();
+
         // 5. Register the student in some courses
+        s1.addCourse(c1);
+        s1.addCourse(c2);
+        s1.addCourse(c3);
+
+        s1.showRegisteredCourses();
+
         // 6. Drop one course
+        s1.dropCourse(c2);
+
         // 7. Print the final registered course list
+        s1.showRegisteredCourses();
+
+        regSys.showAllCourses();
     }
-}
+}