If all you need is the coordinates here is a drawing tool I like to use – move the polygon or re-shape it and the coordinates will display right below the map: jsFiddle here.
Also, here is a Codepen
JS
var bermudaTriangle;
function initialize() {
var myLatLng = new google.maps.LatLng(33.5190755, -111.9253654);
var mapOptions = {
zoom: 12,
center: myLatLng,
mapTypeId: google.maps.MapTypeId.RoadMap
};
var map = new google.maps.Map(document.getElementById('map-canvas'),
mapOptions);
var triangleCoords = [
new google.maps.LatLng(33.5362475, -111.9267386),
new google.maps.LatLng(33.5104882, -111.9627875),
new google.maps.LatLng(33.5004686, -111.9027061)
];
// Construct the polygon
bermudaTriangle = new google.maps.Polygon({
paths: triangleCoords,
draggable: true,
editable: true,
strokeColor: '#FF0000',
strokeOpacity: 0.8,
strokeWeight: 2,
fillColor: '#FF0000',
fillOpacity: 0.35
});
bermudaTriangle.setMap(map);
google.maps.event.addListener(bermudaTriangle, "dragend", getPolygonCoords);
google.maps.event.addListener(bermudaTriangle.getPath(), "insert_at", getPolygonCoords);
google.maps.event.addListener(bermudaTriangle.getPath(), "remove_at", getPolygonCoords);
google.maps.event.addListener(bermudaTriangle.getPath(), "set_at", getPolygonCoords);
}
function getPolygonCoords() {
var len = bermudaTriangle.getPath().getLength();
var htmlStr = "";
for (var i = 0; i < len; i++) {
htmlStr += bermudaTriangle.getPath().getAt(i).toUrlValue(5) + "<br>";
}
document.getElementById('info').innerHTML = htmlStr;
}
HTML
<body onload="initialize()">
<h3>Drag or re-shape for coordinates to display below</h3>
<div id="map-canvas">
</div>
<div id="info">
</div>
</body>
CSS
#map-canvas {
width: auto;
height: 350px;
}
#info {
position: absolute;
font-family: arial, sans-serif;
font-size: 18px;
font-weight: bold;
}