Предмет: Математика, автор: slavacirlan

На рисунке угол 1=2 , угол 3=4=90 гр, BD=DC. Докажите  , сто треугольник  ABC равнобедреный

Приложения:

Ответы

Автор ответа: KuOV
0
Сумма острых углов прямоугольного треугольника равна 90°.
ΔEBD: ∠EBD = 90° - ∠1
ΔFCD: ∠FCD = 90° - ∠2
так как ∠1 = ∠2 по условию, то и
∠EBD = ∠FCD.
Значит ΔАВС равнобедренный по признаку равнобедренного треугольника.
Приложения:
Предыдущий вопрос
Следующий вопрос
Интересные вопросы
Предмет: Английский язык, автор: rgnmur
Можете придумать 5 видов вопросов к этому тексту?

THE DIFFICULTIES OF A FOREIGN LANGUAGE. There are numerous anecdotes about the difficulties of people travelling in foreign countries without knowledge of the language of that country. Here’s the story of a Frenchman travelling in the United States who, while eating in a restaurant, wished to order some mushrooms. Unable to make himself understood, he asked for a pencil & paper & carefully drew a picture of a mushroom. His drawing, however, was not too good, for the puzzled waiter returned in about ten menu not with an order of mushrooms, but with a large man’s umbrella. Another similar story concerns two Americans travelling in Spain. They were both unable to speak a word of Spanish & one day, while eating in a restaurant in a small village, they were having considerable difficulty in explaining to the waiter what they wanted. One of them wanted a glass of milk. The waiter seemed unable to understand. Finally, on the back of the menu the man drew a picture of a cow. The poor waiter, however, still seemed puzzled. Finally he left & was gone from the restaurant for half an hour or so. He returned very pleased with himself. There were two tickets for a bullfight in his hand.
6 лет назад
Предмет: Математика, автор: minramil28
13/20 и 2/5 СРАВНИТЬ СРОЧНО!!!
6 лет назад
Предмет: Английский язык, автор: leuskinadasa131
Exercise 2. Continue the sentences.

1.All the three children in the Greens family are

a) students. b) pupils c) farmers.

2. Now the Greens are in

a) Africa .b) America. c) Australia.

3. In Australia January, February, March and April are

a) winter months. b) spring months. c) summer months.

4. All the pupils in the village school have

a) one teacher. b) many teachers. c) two teachers.

плиз​
6 лет назад
Предмет: Химия, автор: Nike280796
Какие значения принимают квантовые числа для каждого из электронов 3р-подуровня. Решите и сфоткайте плииз
10 лет назад
Предмет: Химия, автор: alina468
какому количеству веществ соответствует порция сахара в которой содержатся 3*10^^23молекул сахара
10 лет назад