Region categorizer [PHP]

example.php

<?php
$regions = new Regions('General');
$regions->add('North', 54.5742270, -1.2349560);
$regions->add('North West', 53.9690089, -2.6276908);
$regions->add('East Anglia', 52.6308859, 1.2973550);
$regions->add('Midlands', 52.6368778, -1.1397592);
$regions->add('Wales', 52.1306607, -3.7837117);
$regions->add('South East', 50.7680350, 0.2904720);
$regions->add('Scotland', 56.4906712, -4.2026458);
$regions->add('South West', 50.7772135, -3.9994610);
$regions->add('Ireland', 53.4129100, -8.2438900);

echo $regions->calculate($_GET['lat'], $_GET['lng']);

regions.php

<?php

class Regions
{
	private $regions = array();
	private $default = false;

	public function __construct($default = false)
	{
		$this->default = $default;
	}

	/**
	 * @return void
	 */
	public function add($name, $lat, $lng)
	{
		$this->regions[] = array('name' => $name, 'lat' => $lat, 'lng' => $lng);
	}

	/**
	 * @return string/false
	 */
	public function calculate($lat, $lng)
	{
		if (count($this->regions) > 0) {
			$nearest = $this->regions[0];
			foreach ($this->regions as $region) {
				$nearDist = $this->dist($nearest['lat'], $nearest['lng'], $lat, $lng);
				$currentDist = $this->dist($region['lat'], $region['lng'], $lat, $lng);
				if ($currentDist < $nearDist) {
					$nearest = $region;
				}
			}
			return $nearest['name'];
		}
		return false;
	}

	/**
	 * @return float
	 */
	private function dist($x1, $y1, $x2, $y2)
	{
		$xval = pow($x2 - $x1, 2);
		$yval = pow($y2 - $y1, 2);
		return sqrt($xval + $yval);
	}
}