Учебный проект "Координатная плоскость"(Тихоновой)

http://wiki.pskovedu.ru/index.php/%D0%A3%D1%87%D0%B5%D0%B1%D0%BD%D1%8B%D0%B9_%D0%BF%D1%80%D0%BE%D0%B5%D0%BA%D1%82_%D0%9A%D0%BE%D0%BE%D1%80%D0%B4%D0%B8%D0%BD%D0%B0%D1%82%D0%BD%D0%B0%D1%8F_%D0%BF%D0%BB%D0%BE%D1%81%D0%BA%D0%BE%D1%81%D1%82%D1%8C