title: I declared PI ,read alpha, but it doesn't get into the instruction. Why it doesn't print 0?
body: <pre><code>scanf("%lf",&amp;alpha);
  
  alpha = (alpha * PI)/180;
  
  if(alpha==PI/2)
  
  {
  
  printf("0");
  
  }
  </code></pre>
  
  <p>i also defined PI and declared alpha...it just skipping this if and i don't know why</p>