Предмет: Геометрия, автор: viktoriakeda

СРОЧНО ПОМОГИТЕ!!!1!1!!1111!!1!!!!!
Отрезок AD-биссектриса треугольника ABC. Через точку D проведена прямая, параллельная стороне AB и пересекающиеся стороны AC в точке F. Доказать, что треугольник ADF - равнобедренный.

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Автор ответа: catdog35687

0

AC||FD, значит угол1= углу3 (как соответственные углы). угол2 = углу4 (накрест лежащие углы). угол1=углу2 , угол1 = углу3, угол2 = углу4, тогда угол1 =углу4 , т.е. уголEDF- ровнобедренный по признаку и AF=FD.

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