PHP: Displaying text and a simple calculation

Output from PHP code below:

PHP Demo
05-18-24
Your IP Address is 13.58.182.29

If Height=50px and Width=20px, then area is 1000

PHP Code:

<?php
echo "PHP Hello Demo<br />";
echo date("m-d-y");
echo "<br />";
$IP_address= getenv("REMOTE_ADDR");
echo "Your IP Address is $IP_address";
echo "<br /><br />";
$width = "50";
$height = "20";
echo "If Height=50px and Width=20px, then area is ";
echo $width * $height " px";
?>