title: parameter1.c:4:6: note: expected ‘double *’ but argument is of type ‘double’
body: <p>I have problem with this:</p>
  
  <pre><code>parameter1.c: In function ‘main’:
  parameter1.c:13:2: error: incompatible type for argument 2 of ‘Countcircumferenceofcircle’
  parameter1.c:4:6: note: expected ‘double *’ but argument is of type ‘double’
  </code></pre>
  
  <p>here is the code:</p>
  
  <pre><code>#include &lt;stdio.h&gt;
  #define phi 3.14
  
  void Countcircumferenceofcircle(int radius, double *C) {
      *C = 2*phi*radius;
  }
  
  int main (void) {
      int r;
      double Circumference;
  
      printf("Insert radius:");
      scanf("%d", &amp;r);
  
      Countcircumferenceofcircle(r, Circumference);
      printf("Circumference=%f\n", Circumference);
  
      return 0;
  }
  </code></pre>
  
  <p>i need your help to solve this.</p>