title: Call to undefined function pi()
body: <p>I am using Borland C++Builder 3.</p>
  
  <p>I have included <code>math.h</code> in my code.</p>
  
  <p>When using this code:</p>
  
  <pre><code>float b;   
  b=pi();
  </code></pre>
  
  <p>I get the following compiler error: </p>
  
  <blockquote>
    <p>call to undefined function pi()</p>
  </blockquote>