Hi

How can I add PHP code in this page?
Thank you

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for example i want to put this code in a new page:
PHP Code:
<form action="<?php $_SERVER['PHP_SELF']; ?>" method="get">
Diametre-Inter: <input type="text" name="Diametre-Inter"><br>
Diametre-Exter: <input type="text" name="Diametre-Exter"><br>
Division: <input type="text" name="division"><br>
<input type = "submit" value = "Calculer">
</form>
Diametre Interrieur: <?php echo $_GET["Diametre-Inter"]; ?><br>
Diametre Exterieur: <?php echo $_GET["Diametre-Exter"]; ?><br>
Division: <?php echo $_GET["division"]; ?><br>
<?php
$rayon_Inter = $_GET["Diametre-Inter"]/2;
$rayon_Exter = $_GET["Diametre-Exter"]/2;
$divis = $_GET["division"];
for($i=0 ; $i<=360;$i+=360/$divis){
$r = deg2rad ($i);
$k = cos($r) * $rayon_Inter;
$l = sqrt ( pow($rayon_Exter,2)-pow ($k,2));
$x = $rayon_Exter - $l;
echo $x . "<br>";
}
echo "<hr>";
echo $rayon_Inter . "<br>";
echo $rayon_Exter . "<br>";
echo "<hr>";
?>