using System;
using static System.Console;

class Circle
{
    public int Radius { get; set; } = 10;
}

class Rectangle
{
    public int Length { get; set; }
    public int Height { get; set; }
}

class PatternMatchingWithSwitch
{
    static void Main()
    {
        PrintShape(new Circle());                               //원
        PrintShape(new Rectangle { Length = 20, Height = 10 }); //직사각형
        PrintShape(new Rectangle { Length = 10, Height = 10 }); //정사각형
    }

    static void PrintShape(object shape)
    {
        switch (shape)
        {
            case Rectangle s when (s.Length == s.Height):
                WriteLine($"정사각형 : {s.Length} x {s.Height}");
                break;
            case Rectangle r:
                WriteLine($"직사각형 : {r.Length} x {r.Height}");
                break;
            case Circle c:
                WriteLine($"원 : 반지름({c.Radius})");
                break;
            case null:
                throw new ArgumentNullException(nameof(shape));
            default:
                WriteLine("<기타 도형>");
                break;
        }
    }
}