Need help ..... Please give some examples of nested for loop in c

#include<stdio.h>
#include<conio.h>
main()
{
int i,j,lines;
char ch = '*';

clrscr();
printf("Enter number of lines : ");
scanf("%d",&lines);

    for(i=0;i <=lines;i++)
    {
    printf("n");
        for (j=0;j < i;j++)
           printf("%c",ch);
    }
getch();
}
</conio.h></stdio.h>

#include <stdio.h>
 
int main()
{
   int row, c, n, temp;
 
   printf("Enter the number of rows in pyramid of stars you wish to see ");
   scanf("%d",&n);
 
   temp = n;
 
   for ( row = 1 ; row <= n ; row++ )
   {
      for ( c = 1 ; c < temp ; c++ )
         printf(" ");
 
      temp--;
 
      for ( c = 1 ; c <= 2*row - 1 ; c++ )
         printf("*");
 
      printf("\n");
   }
 
   return 0;
}

</stdio.h>