Row(
children : [
Flexible( child: Container(color : Colors.blue), flex: 3),
Flexible( child: Container(color : Colors.blue), flex: 7)
]
)
Row(
children : [
Expanded( child : Container(color : Colors.blue), flex: 1),
Container(Color : Colors.green, width : 100)
]
)
하나의 박스만 가로폭을 꽉 채우고 싶을 때 사용