#include <stdio.h>  // include functions in stdio.h

float squareit(float); // prototype: takes float, returns float.

int main()  // header for funciton main
{
  float aa, bb=8;  // declare two floats, initialze bb to 8
  aa=squareit(bb); // send value of bb to funciton squareit()
                   // assign the result to mem location of aa
   
  printf("%.1f\n",aa); // output aa as a float 
  
  return 0;
}

float squareit(float zz)
{
  return zz*zz;
}