ybakos

import 'package:flutter/material.dart';

void main() => runApp(App());

class App extends StatefulWidget {
   @override
   State createState() => AppState();
}

class AppState extends State<App> {

ybakos

import 'package:flutter/material.dart';

void main() => runApp(App());

class App extends StatelessWidget {
 
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
        debugShowCheckedModeBanner: false,

ybakos

import 'package:flutter/material.dart';

void main() => runApp(App());

class App extends StatelessWidget {
  
  // TODO: Declare a Map containing two routes,
  //       one for Exercise and one for Alpha.
  
 

ybakos

You can't rotate the DartPad -- but you can resize the browser window!
Try making it narrower and wider.

ybakos

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';

void main() {
  SystemChrome.setPreferredOrientations([
    DeviceOrientation.portraitUp,
    DeviceOrientation.landscapeLeft,
    DeviceOrientation.landscapeRight
  ]);
  runApp(App());

ybakos

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';

void main() {
  SystemChrome.setPreferredOrientations([
    DeviceOrientation.portraitUp, DeviceOrientation.landscapeLeft, DeviceOrientation.landscapeRight
  ]);
  runApp(App());
}

ybakos

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';

void main() {
  SystemChrome.setPreferredOrientations([
    DeviceOrientation.portraitUp, DeviceOrientation.landscapeLeft, DeviceOrientation.landscapeRight
  ]);
  runApp(App());
}

ybakos

import 'package:flutter/material.dart';

void main() => runApp(App());

class App extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      home: Scaffold(

ybakos

import 'package:flutter/material.dart';

void main() => runApp(App());

class App extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      home: Scaffold(

ybakos

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
        debugShowCheckedModeBanner: false,
        home: Scaffold(body: Center(child: MyWidget()),