<?php

$a = array("x" => 3, "y" => 2);
$b = array("x" => 5, "y" => 7);

function distance ($a, $b) {
   return sqrt(($a["x"]-$b["x"])*($a["x"]-$b["x"]) + ($a["y"]-$b["y"])*($a["y"]-$b["y"]));
}

print ("Distance between a and b is " . distance($a, $b));

?>