Resolução do exercicio


import 'package:flutter/material.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});
  final double _widthHeightMax = 150;
  final double _widthHeightMid = 75;
  final double _widthHeight100 = 100;
  final double _widthHeight55 = 55;
  final double _widthHeight37 = 37;

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      home: Column(
        mainAxisAlignment: MainAxisAlignment.spaceEvenly,
        children: [
          Row(
            mainAxisAlignment: MainAxisAlignment.spaceEvenly,
            children: [
              Stack(
                alignment: Alignment.topRight,
                children: [
                  Container(
                      width: _widthHeightMax,
                      height: _widthHeightMax,
                      color: Colors.red),
                  Container(
                      width: _widthHeightMid,
                      height: _widthHeightMid,
                      color: Colors.blue),
                ],
              ),
              Stack(
                children: [
                  Container(
                      width: _widthHeightMax,
                      height: _widthHeightMax,
                      color: Colors.green),
                  Container(
                      width: _widthHeightMid,
                      height: _widthHeightMid,
                      color: Colors.black),
                ],
              ),
            ],
          ),
          Row(
            mainAxisAlignment: MainAxisAlignment.spaceEvenly,
            children: [
              Stack(
                alignment: Alignment.centerLeft,
                children: [
                  Container(
                      width: _widthHeight100,
                      height: _widthHeight100,
                      color: Colors.black87),
                  Container(width: 55, height: 55, color: Colors.yellow),
                  Container(width: 37, height: 37, color: Colors.brown),
                ],
              ),
              Stack(
                alignment: Alignment.center,
                children: [
                  Container(
                      width: _widthHeight100,
                      height: _widthHeight100,
                      color: Colors.purple),
                  Container(
                      width: _widthHeight55,
                      height: _widthHeight55,
                      color: Colors.white),
                  Container(
                      width: _widthHeight37,
                      height: _widthHeight37,
                      color: Colors.orange),
                ],
              ),
              Stack(
                alignment: Alignment.centerRight,
                children: [
                  Container(
                      width: _widthHeight100,
                      height: _widthHeight100,
                      color: Colors.amber),
                  Container(
                      width: _widthHeight55,
                      height: _widthHeight55,
                      color: Colors.greenAccent),
                  Container(
                      width: _widthHeight37,
                      height: _widthHeight37,
                      color: Colors.white38),
                ],
              ),
            ],
          ),
          Row(
            mainAxisAlignment: MainAxisAlignment.spaceEvenly,
            children: [
              Stack(
                alignment: Alignment.bottomLeft,
                children: [
                  Container(
                      width: _widthHeightMax,
                      height: _widthHeightMax,
                      color: Colors.teal),
                  Container(
                      width: _widthHeightMid,
                      height: _widthHeightMid,
                      color: Colors.yellow),
                ],
              ),
              Stack(
                alignment: Alignment.bottomRight,
                children: [
                  Container(
                      width: _widthHeightMax,
                      height: _widthHeightMax,
                      color: Colors.purple),
                  Container(
                      width: _widthHeightMid,
                      height: _widthHeightMid,
                      color: Colors.lime),
                ],
              ),
            ],
          ),
        ],
      ),
    );
  }
}