A program to print the numbers from 1 to 10 and their squares.

#include 

int main()
{
 int i;

 for(i = 1; i <= 10; i = i + 1)
  printf("%d  %d\n", i, i * i);

 return 0;
}

Exercise 4. Write a program to print a simple triangle of asterisks.

#include "stdio.h"

int main()
{
 int i, j;

 for(i = 1; i <= 10; i = i + 1)
  {
  for(j = 1; j <= i; j = j + 1)
   printf("*");
  printf("\n");
  }

 return 0;
}