HW: Classes
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1. Create the class student that includes the following information about student: name, age and gpa.

Write the following members functions:
(a) Constructor that creates objects of the student class.
(b ) read that prompts the user to enter from the keyboard student name, age and gpa. To terminate reading the user should enter the EOF (ctrl-D in Unix and Ctrl-Z in DOS).
(c ) show that displays on the screen student name, age and gpa.
(d) writefile that writes a record (name, age, gpa) into the file student.dat.
(e) getgpa that returns gpa of the student.
(f) readfile that reads the student record from the file student.dat .

Write a main program that demonstrates the work with this class. Declare all necessary objects and variables. Using read and writefile create the student.dat. After closing the file student.dat reopen it for reading. Read and display all students from the file and compute and display the average gpa for all of them.

2. Create the class triangle that includes three sides of a triangle.

Write the following members functions:
(a) triangle – constructor that creates objects of that class.
(b ) readfile that reads 3 sides from the file triangle.dat. Read until the EOF is detected.
(c ) show that displays on the screen 3 sides of triangle, perimeter and area.
(d) isequilateral that checks whether the triangle is equilateral (it must be a triangle and all sides must be equal.)

Create the input file triangle.dat using an editor and insert values needed for testing of all functions. Write a main program that demonstrates the work with this class. Declare all objects and variables. Display only equilateral triangles from the input file.

Use the following formulas:
Perimeter = a+b+c
Area = sqrt(s*(s-a)*(s-b )*(s-c)), where s=(a+b+c)/2 is the semi-perimeter.