How to get data to build a Google Maps polygon?

Question

JavaScript

Please tell me what are the ways to get data to create a polygon on a Google Maps map. In the examples in the documentation, this is an array of objects, each representing a point with a latitude and longitude

var triangleCoords = [
    {lat: 25.774, lng: -80.190},
    {lat: 18.466, lng: -66.118},
    {lat: 32.321, lng: -64.757},
    {lat: 25.774, lng: -80.190}
  ];

What tools exist for obtaining such an array of data to create a polygon in any district of Moscow, for example, the Central Administrative District?