public void ValidateAndCalculateArea(ILogger logger, List <Point> points) { double result = AreaCalculator.GetCalculationAreaResult(points); if (result > 0) { MessageBox.Show("Square of area is " + result); } else if (result == -1) { MessageBox.Show("Invalid value for points were inputed"); } else if (result == 0) { MessageBox.Show("Calculating of area square is incorrect"); } }