ГДЗ по геометрии 7 класс Мерзляк Задание 249

\[Схематический\ рисунок.\]

\[Дано:\ \ \]

\[AB = BC = CD = DE = EF.\]

\[Найти:\]

\[AB\ :CF;\ AB\ :BF;\ BD\ :AE.\]

\[Решение.\]

\[1)\ CF = CD + DE + EF =\]

\[= AB + AB + AB = 3AB;\]

\[AB\ :CF = 1\ :3.\]

\[2)\ BF = BC + CD + DE + EF =\]

\[= AB + AB + AB + AB = 4AB;\]

\[AB\ :BF = 1\ :4.\]

\[3)\ BD = BC + CD =\]

\[= AB + AB = 2AB;\]

\[AE = AB + BC + CD + DE =\]

\[= AB + AB + AB + AB = 4AB;\]

\[BD\ :AE = 1\ :2.\]

\[Ответ:\ \ AB\ :CF = 1\ :3;\ \]

\[\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ AB\ :BF = 1\ :4;\ \]

\[\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ BD\ :AE = 1\ :2.\]