Discussion on question by Александр: Python. Помогите с заданием на площадь

Imported from a comment discussion on https://ru.stackoverflow.com/questions/1592724/python-%d0%9f%d0%be%d0%bc%d0%be%d0%b3%d0%b8%d1%82%d0%b5-%d1%81-%d0%b7%d0%b0%d0%b4%d0%b0%d0%bd%d0%b8%d0%b5%d0%bc-%d0%bd%d0%b0-%d0%bf%d0%bb%d0%be%d1%89%d0%b0%d0%b4%d1%8c