how to create a circle object in flutter code example

Example 1: circle container flutter

Container(
	height: 300,
    width: 300,
    decoration: BoxDecoration(
                 border: Border.all(
                 color: Colors.red[500],
                	),
                 shape: BoxShape.circle,
               ),
    child: ...,
    ),

Example 2: circle around icon flutter

CircleAvatar(
   backgroundColor: Colors.white,
   radius: 30,
   child: Icon(Icons.add),
),