JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://maps.googleapis.com/maps/api/js?key=AIzaSyAYtvzvTrCagXcnPFVDY1Bz7HSH_7Kidv0&amp;libraries=geometry"></script>
<div id="map"></div>

CSS

html,
body {
  height: 100%;
  margin: 0;
  padding: 0;
}

#map {
  height: 100%;
}

JavaScript

//must load geometry library in google maps API request libraries=geometry
function initialize() {
  var map = new google.maps.Map(document.getElementById('map'), {
    center: {
      lat: 41.345947,
      lng:  2.149434
    },
    zoom: 15,
  });
  var polygonCoords = [{
    lat: 41.345947,
    lng: 2.149434
  }, {
    lat: 41.345659,
    lng: 2.148954
  }, {
    lat: 41.343916,
    lng: 2.147819
  }, {

    lat: 41.343691,
    lng: 2.147787
  }, {
    lat: 41.343328,
    lng: 2.148641
  }, {
    lat: 41.343077,
    lng: 2.150446
  }, {
    lat: 41.346502,
    lng: 2.150955
  }, {
    lat: 41.346446,
    lng: 2.151627
  }, {
    lat: 41.347042,
    lng: 2.151698
  }, {
    lat: 41.347184,
    lng: 2.151047
  }, {
    lat: 41.346954,
    lng: 2.150173
  }, {
    lat: 41.345865,
    lng: 2.149828
  }, {
    lat: 41.345947,
    lng: 2.149434
  }];
  
  const cityCircle = new google.maps.Circle({
      strokeColor: "#FF0000",
      strokeOpacity: 0.8,
      strokeWeight: 2,
      fillColor: "#FF0000",
      fillOpacity: 0.35,
      map,
      center: {lat: 41.340142, lng: 2.149115},
      radius: 50,
    });
   
  new google.maps.Circle({
      strokeColor: "#FF0000",
      strokeOpacity: 0.8,
      strokeWeight: 2,
      fillColor: "#FF0000",
      fillOpacity: 0.35,
      map,
      center: {lat: 41.338361, lng: 2.144700},
      radius: 50,
    });

  var polygonObject = new google.maps.Polygon({
    paths: polygonCoords,
    strokeColor: '#FF0000',
    strokeOpacity: 0.8,
    strokeWeight: 2,
    fillColor: '#FF0000',
    fillOpacity: 0.35
  });
  polygonObject.setMap(map);


  var testPointCoords = new google.maps.LatLng(41.344638, 2.149551);

	
  var resultColor =
    google.maps.geometry.poly.containsLocation(testPointCoords, polygonObject) ?
    'green' :
    'red';

  var testPointObject = new google.maps.Marker({
    position: testPointCoords,
    map: map,
    icon: {
      path: google.maps.SymbolPath.CIRCLE,
      fillColor: resultColor,
     ...