while (!correct)
    {   

        cout < "Please enter an angle value => ";
        cin >> value; //request user to input a value

        if(cin.fail()) // LINE 7
        {
            cin.clear(); // LINE 9
            while(cin.get() != '\n'); // LINE 10
            textcolor(WHITE);
            cout < "Please enter a valid value. "< endl;
            correct = false;

        }
        else
        {
            cin.ignore(); // LINE 18
            correct =true;
        }
    }