import 'package:flutter/material.dart';
void main() {
  runApp(MaterialApp(
    home: MyApp(),
  ));
}
class MyApp extends StatefulWidget {
  @override
  _State createState() => _State();
}
class _State extends State<MyApp> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Row Widget'),
      ),
      body: Container(
        height: 1000,
        child: Row(
          mainAxisAlignment: MainAxisAlignment.start,
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: <Widget>[
            Container(
              color: Colors.red,
              height: 100,
              width: 100,
            ),
            Container(
              color: Colors.green,
              height: 100,
              width: 100,
            ),
            Container(
              color: Colors.orange,
              height: 100,
              width: 100,
            ),
          ],
        ),
      ),
    );
  }
}