Предмет: Алгебра, автор: igorsharow0

Алгебра!!!! 7 класс. Помогите пожалуйста

Приложения:

Ответы

Автор ответа: Ch1raqq

Ответ:

∠BAC = 30°

∠CBA = 60°

AB = 7

Объяснение:

∠CBA = ∠EBD = 60°(вертикальные углы)
∠BAC = 180 - 60 - 90 = 30°
т.к. ΔABC - прямоугольный, а ∠BAC = 30°
AB = 2BC = 7 (т.к. в прямоугольном треугольнике сторона, лежащая напротив угла в 30°, равна половине гипотенузы, в данном случае AB - гипотенуза)

igorsharow0: Спасибо

Предыдущий вопрос

Следующий вопрос

Похожие вопросы

Предмет: Русский язык, автор: remmoz

Составь предложение со словами ученик, класс в винительном падеже

1 год назад

Предмет: Английский язык, автор: vlada267

правила на улице на английском 10 правил

1 год назад

Предмет: Английский язык, автор: mariana333

Choose the right tenses (Present Continuous, Present Simple, Present Perfect).

1. Jack … (always, have) colds and chest problems and his cough is irritating.

2. Anne … (fly) to Paris on Monday for a holiday. Her flight … (take) off at 8.15 in the morning and … (arrive) in Paris at 9.15.

3. Eric … (see) his dentist tonight. He … (already, make) an appointment.

4. I don't like this meat. It … (taste) so salty.

5. Don't pay attention to little Kate. She … (just, be) awfully noisy these days.

6. The world population … (grow) and it's really a big problem for our planet.

7. Mr. Brown … (attend) a seminar on Tuesday. He … (already, make) a report.

8. Barbara … (constantly, cause) trouble at work. What … (happen) to her?

9. Dave … (play) football professionally for very long.

10. Claudia … (like) sport. She … (always, like) sport.

11. How many glasses of juice … (you, drink) today?

12. I … (know) what you … (mean). You … (appear) to have a problem.

13. This is the first time Mark … (drive) a car.

14. It … (snow) again. It … (snow) all the time here in winter.

15. The dog … (smell) meat. This is the third time she … (do) this.

16. Little Larry is dirty from head to foot because he … (play) in the mud.

17. Sonya … (try) to study. She … (try) to focus her attention on the text for the last hour, but her next-door neighbour … (make) a noise. He … (seem) to interrupt her.

18. Rosa … (read) the book for several months, but she … (not, finish) reading it yet.

19. Ted … (not, do) his homework so far. He … (still, continue) doing it.

20. Tony … (be) ill since he came back from his holiday.