This code will help you.
Program:
using System;
class FloydsTriangle1
{
public static void Main()
{
int i,j,k=1;
Console.WriteLine(" *** Floyd''s Triangle - Normal Numeric Mode **** ");
for (i=1; i<=13; i++)
{ // 13 is the height of the triangle
for (j=1; j<i+1; j++)
{ // each time the number per line is incremented by 1
Console.Write(k++ + " "); // k is the actual data (number) which will be printed.
}
Console.Write("\n"); // then we go to the next line.
}
Console.ReadLine();
}