main.dart

double totalDistance = 0.0;

// Calculating the total distance by adding the distance
// between small segments
for (int i = 0; i < polylineCoordinates.length - 1; i++) {
  totalDistance += _coordinateDistance(
    polylineCoordinates[i].latitude,
    polylineCoordinates[i].longitude,
    polylineCoordinates[i + 1].latitude,
    polylineCoordinates[i + 1].longitude,
  );
}

// Storing the calculated total distance of the route
setState(() {
  _placeDistance = totalDistance.toStringAsFixed(2);
  print('DISTANCE: $_placeDistance km');
});