Seems like a weird way to draw a rectangle, but anyway...
Code:
using System;
namespace ConsoleApplication4
{
class Program
{
static void Main()
{
Console.Write("select the length of the sides: ");
int len;
if (!int.TryParse(Console.ReadLine(), out len))
Main(); // invalid input
if (len < 1 || len > 20)
Main(); // invalid input
for (int i = 0; i < len; i++)
{
if (i == (len - 1) || i == 0) // first or last line
Console.WriteLine(Repeater("* ", len));
else // middle line
Console.WriteLine("* " + Repeater(" ", (len - 2)) + "* ");
}
Console.WriteLine();
Main();
}
static String Repeater(String text, int count)
{
String tmp = "";
for (int i = 0; i < count; i++)
tmp += text;
return tmp;
}
}
}