using System;

using System.Text;

​

public class Program

{

    public static void Main()

    {

        //This program is changed a bit. It allows the user to choose the height of the triangle.

            //For output with exactly 9 symbols - as it is in the task, you can enter 4 for height.

            //The code is devided in three logical parts - first one prints the edge, the second one

            //shows the lines between the edge and the base and the last one displays the base of the triangle.

            try

            {

                Console.OutputEncoding = Encoding.UTF8; // This code allows correct output for symbols

                char symbol = '\x00A9';

                byte triangleHeight;

                //The following loop guarantees minimal height because it has to be at least 3

                do

                {

                    Console.Write("Enter height of the triangle: ");

                    triangleHeight = byte.Parse(Console.ReadLine());

                } while (triangleHeight <= 2);

                int numberSymbolsBase = triangleHeight; // This is the number of symbols for the base without spaces

                if (triangleHeight * 2 > Console.BufferWidth || triangleHeight > Console.BufferHeight)

                {

                    Console.SetBufferSize(2 * triangleHeight, triangleHeight + 5);

                    //This code sets the size of the buffer according to the dimensions of the triangle,

                    //but only if needed

                }

                // Edge of the triangle

                string spacesBeforeEdge = new string(' ', triangleHeight - 1);

                string edge = spacesBeforeEdge + symbol;

                Console.WriteLine(edge);

                // Lines Between the edge and the base of the triangle

                int spacesBetweenCount = 1; // This variable is used for the speces in the triangle

                int spacesBeforeCount = triangleHeight - 2; //Spaces before each line of symbols

                for (int i = 1; i <= triangleHeight - 2; i++)

                {

                    string spacesBefore = new string(' ', spacesBeforeCount);

                    spacesBeforeCount--;

                    string spacesBetween = new string(' ', spacesBetweenCount);

                    spacesBetweenCount = spacesBetweenCount + 2;

                    string currentLine = spacesBefore + symbol + spacesBetween + symbol;

                    Console.WriteLine(currentLine);

                }

                // Base of the triangle

                for (int i = 1; i <= numberSymbolsBase; i++)

                {

                    Console.Write(symbol + " ");

                }

                Console.WriteLine();

            }

            catch (FormatException)

            {

                Console.WriteLine("Wrong format for height."); ;

            }

            catch (OverflowException)

            {

                Console.WriteLine("You have entered too big or negative number for height.");

            }

    }

}

​

​