polygon

A polygon is a list of linear rings which are each made up of a list of vertices.

Each vertex is a 2-dimensional point of the form: [longitude, latitude]. This is represented as an array of doubles of length 2 (so [double, double]).

An array of 4 or more vertices, where the first and last vertex are the same (to form a closed boundary), is called a linear ring. The linear ring vertices must be listed in counter-clockwise order around the ring’s interior. The linear ring is represented as an array of vertices, or an array of arrays of doubles ([[double, double], ...]).

A geofence consists of a single linear ring. To allow for future expansion, the Polygon parameter takes an array of linear rings, which is represented as an array of arrays of arrays of doubles ([[[double, double], ...], ...]).

A linear ring for use in geofences can consist of between 4 and 1,000 vertices.