#3RectPerimeterArea

static void Main()
        {
            Console.WriteLine("Enter a random whole number for rectangle's width: ");
            int width = int.Parse(Console.ReadLine());
            Console.WriteLine("Enter a random whole number for rectangle's height: ");
            int height = int.Parse(Console.ReadLine());
            //calculations
            int area = width * height;
            Console.WriteLine("The rectangle's area is: " + area);
            int perimeter = (2 * width) + (2 * height);
            Console.WriteLine("The rectangle's perimeter is: " + perimeter);
        }