circle function
Implementation
circle(Canvas canvas, Size size, double radius) {
var paint = Paint()
..color = const Color(0xffef5777)
..strokeWidth = 3
..style = PaintingStyle.stroke;
var path = Path();
path.addOval(Rect.fromCircle(
center: Offset(size.width / 2, size.height / 2),
radius: radius,
));
canvas.drawPath(path, paint);
}