# Perpendicular Distance

The *perpendicular distance* is defined as the shortest distance between a point
a line (in the two-dimensional plane) respectively between a point and a
great circle on a spherical surface.

With *phpgeo* it is possible to calculate the perpendicular distance between a
point (instance of the `Coordinate`

class) and a
Great Circle - which is defined by a `Line`

. A line is
defined by a pair of coordinates.

The distance between points *P* and *X* is the perpendicular distance in the following sketch:

## Example

```
<?php
use Location\Coordinate;
use Location\Line;
use Location\Utility\PerpendicularDistance;
$point = new Coordinate(52.44468, 13.57455);
$line = new Line(
new Coordinate(52.4554, 13.5582),
new Coordinate(52.4371, 13.5623)
);
$pdCalc = new PerpendicularDistance();
printf(
"perpendicular distance: %.1f meters\n",
$pdCalc->getPerpendicularDistance($point, $line)
);
```

The code above will produce the output below:

```
perpendicular distance: 936.7 meters
```