verticalAlignment property

How the annotation should be aligned vertically in the respective position.

• GaugeAlignment.center aligns the annotation widget to center.
• GaugeAlignment.near aligns the annotation widget to near.
• GaugeAlignment.far aligns the annotation widget to far.

Defaults to GaugeAlignment.center.

Also refer GaugeAlignment

Widget build(BuildContext context) {
   return Container(
       child: SfRadialGauge(
         axes:<RadialAxis>[RadialAxis
           annotations: <GaugeAnnotation>[
           GaugeAnnotation(widget: Text('Annotation'),
           verticalAlignment: GaugeAlignment.far)])]
       ));
}