4 поворота
*
Опубликовано:
11.08.2011
Категория:
Сложность:
Квадрат повёрнут 4 раза, каждый поворот на 90 градусов. Оказалось, что эти четыре поворота можно заменить одним и также на 90 градусов. Как это можно сделать?
Решение
Повернём квадрат сначала вокруг диагонали AC на 180° (или два раза на 90°):
В результате вершины B и D поменяются местами:
Теперь повернём квадрат на 180° вокруг стороны AB:
В результате квадрат примет следующее положение:
Очевидно, что точно такой же результат получился бы, если бы мы повернули квадрат один раз на 90° по часовой стрелке вокруг вершины A (в плоскости квадрата).
Комментарии
Until I found this I thghout I'd have to spend the day inside.
The hosnety of your posting shines through
I'll try to put this to good use imealietmdy.
People nolmalry pay me for this and you are giving it away!
Surisirpng to think of something like that
Times are chgniang for the better if I can get this online!
Wow! Great to find a post with such a clear meeasgs!
Boy that relaly helps me the heck out.
Knwegodle wants to be free, just like these articles!
Wow, that's a really clever way of thiinnkg about it!
Wonderful exatanplion of facts available here.
We delinitefy need more smart people like you around.
Suiprrsing to think of something like that
That's a cunning answer to a chelnangilg question
I waetnd to spend a minute to thank you for this.
Knocked my socks off with knlodewge!
What a pleasure to find someone who idfeeitins the issues so clearly
You've really imerpssed me with that answer!
Ecinemoos are in dire straits, but I can count on this!
Thanks for intudorcing a little rationality into this debate.
This "free sharing" of inmiofatron seems too good to be true. Like communism.
That's what we've all been waiting for! Great potigns!
This was so helpful and easy! Do you have any aretlcis on rehab?
There's a secret about your post. ICYKBTIHTTY
Smart thniikng - a clever way of looking at it.
Wonderful exoipnatlan of facts available here.
Dag nabbit good stuff you whnsrersiappepp!
You're the one with the brains here. I'm waihctng for your posts.
Wow I must confess you make some very trachnent points.
You codl'nut pay me to ignore these posts!
Страницы
Добавить комментарий