97 is the ASCII (American Standred Code for Information Interchange) code of small 'a'. If we increment the character variable then it turn to 98. i.e. 'b'. Now create a row and column
public class Pattern
{
public static void main(String []arg)
{
char ch=97;
int r,c,s,n=5;
for(r=0;r<n;r++)
{
ch=97;
for(s=0;s<n-r;s++)
{
System.out.print(" ");
}
for(c=0;c<=r;c++)
{
System.out.print(ch);
ch++;
}
System.out.println("");
}
}
}