Предмет: Геометрия, автор: nastya168

Длина ребра куба АВСДА1В1С1Д1 равна 4, точка F-середина ДС.найти: а)расстояние между серединами отрезковАF и А1С. б)урол между прямымиСА1 и АF

Ответы

Автор ответа: Dasha101096

Угол между AF и A1C=135 градусов, угол между CA1 и AF=60 градусов

Предыдущий вопрос

Следующий вопрос

Похожие вопросы

Предмет: Математика, автор: Аноним

Сравни обыкновенные дроби: 5/7 и 3/7

7 лет назад

Предмет: Геометрия, автор: liternaty84

ABCD - параллелограмм, K - середина CD, EC = 6 см. Найдите AO

7 лет назад

Предмет: Английский язык, автор: vsezfox

ПОМОГИТЕ ПОЖАЛУЙСТА!!!СРОЧНО!!!
1. Sam's tired. He ** two kilometres.

a) hasn't swum yet b) has just swum c) have swum

2. Rob knows. I ** him the result of the match.

a) have already told b) am telling c) have told already

3. Pat's not very good at riding her bike. **

a) She's fallen off twice b) She's fallen twice off c) She twice has fallen off

4. Our holiday finishes tomorrow and I ** any postcards.

a) haven't wrote b) hasn't written c) haven't written

5. ** your mobile phone in the cinema?

a) Have you used ever b) Did you ever used c) Have you ever used

6. I ** Simon's birthday present. He mustn't find it before tomorrow.

a) have hidden b) have hide c) has hidden

7. Neil's on holiday at the moment.' 'Oh, where **?

a) is he going b) has he went c) has he gone

8. I ** Italian. Now I want to learn Spanish.

a) already have studied b) have already studied c) just have studied

9. Mum and Dad are tired because they ** a long way.

a) have drive b) have driven c) have drove

10. Three years ago I ** any French. Now I'm very good at it.

a) don't speak b) haven't spoken c) didn't speak

11. Tony ** out, but he left a message for you.

a) just has gone b) has just been c) has just gone

12. 'How long has Sonia been unemployed? ***?

a) For two months b) Since two months c) Two months ago

13. Lucy isn't ready to go to school. She ** her breakfast yet.

a) hasn't had b) doesn't have c) hasn't have

14. I'm waiting to hear from Lisa. **?

a) Is she ringing yet b) Has she yet rung c) Has she rung yet

15. How long has Philip been writing books?' **

a) For his birthday b) Since he was a child c) Twenty years ago

16. Will has travelled all over the world, but ** to Ireland.

a) he's never been b) he's gone never c) he's never gone

17. Jon ** his knee, so he can't walk.

a) has hurted b) has hurt c) huited

18. Has Dave ever ** a motorbike?

a) ride b) ridden c) rode

19. Mark ** a cold for a week.

a) has b) is having c) has had

20. David ** in a helicopter, but he'd like to go.

a) has never been b) didn't ever go c) never was

7 лет назад

Предмет: Математика, автор: криш

имелась пачка бумаге . На перепечатывание одной рукописи израсходовали три целых пять десятых пачки. На перепечатывание другой рукописи ушло 0,8 остатка.сколько листов бумаги было в пачке если после перепечатывания этих двух рукописей в ней осталось 40листтов

10 лет назад

Предмет: Математика, автор: Panory

На сколько процентов изменится площадь прямоугольника со сторонами m и n при увеличении одной стороны на 10% и уменьшении другой также на 10%, если :

а) m = 9см, n = 7 см б) m = 15см, n = 12см?

10 лет назад