public double areaMeters() throws GeometryException {
    return Double.isNaN(areaMeters) ? (areaMeters =
      (isPoint() || canBePolygon() || canBeLine()) ? GeoUtils.areaInMeters(latLonGeometry()) : 0) : areaMeters;
  }
Returns the approximate area of the geometry in square meters.
planetiler-core/src/main/java/com/onthegomap/planetiler/geo/WithGeometry.java