(PHP 4, PHP 5)
deg2rad — Converts the number in degrees to the radian equivalent
$number
    )
   This function converts number from degrees
   to the radian equivalent.
  
numberAngular value in degrees
   The radian equivalent of number
  
Example #1 deg2rad() example
<?php
echo deg2rad(45); // 0.785398163397
var_dump(deg2rad(45) === M_PI_4); // bool(true)
?>