Cho góc nhọn xOy vầ điểm M nằm ở miền trong của góc nhọn. Gọi E và F lần lượt là h...">
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4 tháng 9 2023

Để chứng minh QO⋅QMOP⋅PM=HF^2/HE^2, ta sẽ sử dụng định lí hình học và tính chất của các tam giác đồng dạng.

Đầu tiên, ta cần chứng minh tam giác QOM và tam giác MOP đồng dạng. Ta có:

∠QOM = ∠MOP (do chúng là góc đối) ∠OQM = ∠OMP (do chúng là góc ở chung) => Tam giác QOM đồng dạng với tam giác MOP theo định lí góc-góc (AA).

Từ đó, ta có tỷ lệ giữa các cạnh của hai tam giác này:

QM/OP = OQ/OM (tỷ lệ cạnh tương ứng của hai tam giác đồng dạng) => QM = OQ/OM * OP

Tiếp theo, ta cần chứng minh tam giác HEF và tam giác HOM đồng dạng. Ta có:

∠HEF = ∠HOM (do chúng là góc đối) ∠EHF = ∠OHM (do chúng là góc ở chung) => Tam giác HEF đồng dạng với tam giác HOM theo định lí góc-góc (AA).

Từ đó, ta có tỷ lệ giữa các cạnh của hai tam giác này:

HE/OM = EF/OM (tỷ lệ cạnh tương ứng của hai tam giác đồng dạng) => HE = EF/OM * OM => HE = EF

Như vậy, ta có HE = EF.

Bây giờ, ta sẽ xem xét tỷ lệ giữa các đoạn thẳng QO, QM, OP, PM và HF, HE:

QO⋅QMOP⋅PM = (OQ/OM * OP) * (OP) * (PM) = OQ * OP * PM / OM = OQ * PM

Vì HE = EF, nên ta có:

HF/HE = QM/OM (tỷ lệ cạnh tương ứng của hai tam giác đồng dạng HEF và HOM) => HF = QM/OM * HE

Thay giá trị của HE = EF vào, ta có:

HF = QM/OM * EF

Vậy, ta thấy HF^2 = (QM/OM * EF)^2

Như vậy, ta có:

QO⋅QMOP⋅PM = HF^2/HE^2

Vậy, điều phải chứng minh đã được chứng minh.

11 tháng 8 2019

Tìm từ đồng nghĩa
37. Once you have finish reading, you can go on with your work.
A: continue doing
B: continue to do
C: keep do
D: keep to do
38. The doctor wanted to examine the test results with her patient.
A: go over
B: up
C: go on
D: go out
39. The local meeting is on this weekend. Please put it down in your diary.
A: make a note
B: made a note
C: have made a note
D: to make a note
40. You don't need the light on in here. Press the switch, please!
A: turn on
B: turn down
C: turn off
D: turn up
41. My grandfather has recovered form the illness.
A: get over
B: got over
C: to get over
D: getting over
42. She spent her chilhood in a small village in the south.
A: grew up
B: grow up
C: grown up
D: to grow up
43. We are really expecting to see you again pleasure.
A: looking forward to
B: look up
C: look for
D: look after

37. One you have finish reading, you can go on with your work.
A: continue doing
B: continue to do
C: keep do
D: keep to do
38. The doctor wanted to examine the test results with her patient.
A: go over
B: up
C: go on
D: go out
39. The local meeting is on this weekend. Please put it down in your diary.
A: make a note
B: made a note
C: have made a note
D: to make a note
40. You don't need the light on in here. Press the switch, please!
A: turn on
B: turn down
C: turn off
D: turn up
41. My grandfather has recovered form the illness.
A: get over
B: got over
C: to get over
D: getting over
42. She spent her chilhood in a small village in the south.
A: grew up
B: grow up
C: grown up
D: to grow up
43. We are really expecting to see you again pleasure.
A: looking forward to
B: look up
C: look for
D: look after

18.   The Vietnamese people still follow the costumes of giving lucky money to children A                                                   B                   Cduring Tet holidays.       D PART C: READINGRead the passage and choose the correct answer to each of the following questions. (5questions)Fathers used to act as the “breadwinner” of their family, and as the teacher of moral and religious values. Today,...
Đọc tiếp

18.   The Vietnamese people still follow the costumes of giving lucky money to children A                                                   B                   C

during Tet holidays.

       D

 

PART C: READING

Read the passage and choose the correct answer to each of the following questions. (5questions)

Fathers used to act as the “breadwinner” of their family, and as the teacher of moral and religious values. Today, however, those roles are gradually changing.

Changes in economic roles.

More and more women are going out to work and earn money. This increases the budget of the family. Apart from that, there are various social welfare programmer which financially assist mothers in supporting their children. Both these changes have greatly impacted the role of fathers because they make paternal financial support less essential for many families.

Changes in caregiving roles.

With the burden of financial support reduced, and with a changing concept of a father’s role, modern day fathers tend to be more involved in children’s caregiving. They  are now spending more time and energy on their children. Psychological research across families from all ethnic backgrounds suggests that the influence of a father’s love and attention is as great as that of a mother’s. Fatherly love helps children develop a sense of their place in the world, which helps their social and emotional development. Moreover, children who receive more love from their fathers are less likely to have behavioral problems.

This trend is still increasing and its effects will become clearer and clearer in the future, especially in traditionally male-dominated societies.

19.   Which can be the best title for the passage?

 

A.   The changing roles of the modern father.

B.   The changing roles of the modern father in economic.

C.   The changing roles of the modern father in caregiving.

D.   Father as the “breadwinner” of the family.

20.   Social welfare programmer           _.

A.   support families financially                                 B. help mothers with domestic abuse

C. educate fathers about their responsibilities    D. train caregivers

21.   Which of these is NOT the traditional role of a father?

A.   financial supporter                                                B. teacher of moral values

C. religious educator                                               D. caregiver

22.     The word “various” is closest in meaning to           .

A. a few                      B. no                                       C. many                                  D. only

23.     The word “who refers to            .

A. development        B. fathers                               C. mothers                             D. children

 

 

D.WRITING

I. Choose the best sentence that has the same meaning as the first one. (5questions)

24.   There isn’t enough space in the room for another bed.

A.   Not enough space there is in the room for another bed.

B.   Another bed will take up enough space in the room.

C.   The room isn’t big enough for one more bed.

D.   We don’t want any more beds in the room.

25. I often went fishing with my brother when I was a child.

A.I used to go fishing when I was a child.

B.I am used to going fishing when I was a child.

C. I still go fishing with my brother now.

D.I was going fishing when I was a child.

26.   Her mother has just bought for her a new pair of jeans. She has just…………………………………………….. .

A.   bought a new pair of jeans.

B.   been bought a new pair of jeans.

C.   buy a new pair of jeans.

D.   been buying a new pair of jeans.

27. ‘Why don’t you use a password to protect your files?’ An said to me.

A.    An advised me to use a password to protect your files,

B.    An suggested using a password to protect my files.

C.    An encouraged me to use a password to protect my files

D.    An asked me why I didn’t use a password to protect my files.

I.            haven’t got money, so I’m not going on holiday.

A.   Having no money made me going on holiday.

B.   Not having money on my holiday stopped me.

C.    If I have money, I’llgo on holiday.

D.    If I had money, I would go on holiday.

II.  Choose the sentence that is the best make up of the words/ phrases given.

(5questions)

36.   She/ never/ make/ mistakes/ her answers/ because/ careful.

 

A.   She never makes mistakes in her answers because she is careful.

B.   She makes never mistakes in her answers because she is carefully

C.   She never makes mistakes in her answers because of she is careful

D.   She never makes mistakes in her answers because of her careful

37.   Thu / person/ always / help/ me.

A.   Thu is the person whom always helps me.

B.   Thu is the person who always helps me.

C.   Thu is the person whose always helps me.

D.   Thu is the person which always helping me.

38.   I/ look forward/ start/ work/ you.

A.I look forward to starting to work for you

B.I look forwards to start to work for you

C.I am looking forward to start working for you

D.I look forward to start working to you.

39.   I / think / we / turn / light / before / leaving / room.

A.I think we should turn the light before leaving the room.

B.    I think we should turn off the light befere leaving the room.

C. I think we should turn off light before leaving the room.

D. I think we should turn off the light before leaving room.

40.   However/ hard/ she/ try/ couldn’t /pass/ driving test.

A.   However hard she tires, she couldn’t pass the driving test.

B.   However hardly she tries, she couldn’t pass the driving test.

C.   However hard she tries, she couldn’t be passed the driving test.

D.   Hardly however she tries, she couldn’t pass the driving test.

5
17 tháng 11 2021

C(COSTUMES THÀNH COSTUME)

17 tháng 11 2021

Writing

Part I:

24.C     25.A     26.B     27.A     28.C

Part 2:

36.A     37.B     38.C     39.B     40.A

21 tháng 11 2021

Part IV. Rewrite the sentences beginning with “S + wish + S + V2/ed… or Passive form”.

37. I don’t know French.
→___________________________________________________________________________

38. She can take her dog for a walk.
→___________________________________________________________________________

39. My parents live very far from Ho Chi Minh City.
→___________________________________________________________________________

40. You must wash this dress.
→___________________________________________________________________________

41. She isn’t a famous singer.
→___________________________________________________________________________

42. They must prepare meals every day.
→___________________________________________________________________________

 

III: Sắp xếp các từ đã cho thành câu hoàn chỉnh.1. museum / me / the / it’s / to / interesting / go / to / for._________________________________________________________________________________2. dangerous / play / It’s / for / to / children / knife / with.__________________________________________________________________________________ 3. sure / he / my / stolen / I / that / am / has / bike. __________________________________________________________________________________...
Đọc tiếp

III: Sắp xếp các từ đã cho thành câu hoàn chỉnh.

1. museum / me / the / it’s / to / interesting / go / to / for.

_________________________________________________________________________________

2. dangerous / play / It’s / for / to / children / knife / with.

__________________________________________________________________________________

3. sure / he / my / stolen / I / that / am / has / bike.

__________________________________________________________________________________

IV: Viết lại câu sao cho nghĩa không thay đổi.

1. Learning English is no difficult for me.

→ It is_____________________________________________________________________________

2. Jim was very confident when he said that he was the best.

→ Jim was very confident to____________________________________________________________

3. Peter received a letter from his foreign friend yesterday. He was very happy about it.

→ Peter was very happy to_____________________________________________________________

4. I can’t come to your party this weekend. I’m afraid.

→ I am afraid_______________________________________________________________________

5. Doing gardening is not as easy as it looks.

→ It is not__________________________________________________________________________

6. I had no difficulty in making the last decision.

→ It was not ________________________________________________________________________

7. I think Peter is very happy. He has won a lottery.

→ I think Peter is very happy that________________________________________________________

8. You were so lucky. You ran into a famous singer

→ You were so lucky to_______________________________________________________________

1
23 tháng 7 2021

III: Sắp xếp các từ đã cho thành câu hoàn chỉnh.

1. museum / me / the / it’s / to / interesting / go / to / for.

____it's interesting for me to go to the museum

2. dangerous / play / It’s / for / to / children / knife / with.

____it's dangerous for children to play with knife

3. sure / he / my / stolen / I / that / am / has / bike.

___i am sure that he has stolen my bike

IV: Viết lại câu sao cho nghĩa không thay đổi.

1. Learning English is no difficult for me.

→ It is not difficult to learn English_____________________________________________________________________________

2. Jim was very confident when he said that he was the best.

→ Jim was very confident to_say that he was the best___________________________________________________________

3. Peter received a letter from his foreign friend yesterday. He was very happy about it.

→ Peter was very happy to receive a letter from his foreign friend yesterday____________________________________________

4. I can’t come to your party this weekend. I’m afraid.

→ I am afraid_that i can't come to your party this weekend______________________________________________________________________

5. Doing gardening is not as easy as it looks.

→ It is not_easy to do garden_________________________________________________________________________

6. I had no difficulty in making the last decision.

→ It was not _difficult to make the last decision_______________________________________________________________________

7. I think Peter is very happy. He has won a lottery.

→ I think Peter is very happy that__he has won a lottery______________________________________________________

8. You were so lucky. You ran into a famous singer =) you were so lucky to ran into the famous singer

→ You were so lucky to_______________________________________________________________

4 tháng 9 2021

they open the shop longer

4 tháng 9 2021

nhớ chấm cuối câu (một số thầy cô khó tính không thấy có chấm ở cuối câu là không cho điểm đâu)

IV. Put in the correct form of the verbs in brackets. a. Film makers, David Morris (be) interested in the cinema since he (be) a smallchild. He (make) his first film when he (be) just twelve years old. He is now almost40 and he (make) 30 films. David (love) travelling. His work (take) him all over theworld. He (be) to Africa, India, Australia, China, the Usa and South American. Lastyear, he (visit) Russia for the first time. David (be) married to the singer, LenaLennox. They (be) married...
Đọc tiếp
IV. Put in the correct form of the verbs in brackets.
a. Film makers, David Morris (be) interested in the cinema since he (be) a smallchild. He (make) his first film when he (be) just twelve years old. He is now almost40 and he (make) 30 films. David (love) travelling. His work (take) him all over theworld. He (be) to Africa, India, Australia, China, the Usa and South American. Lastyear, he (visit) Russia for the first time. David (be) married to the singer, LenaLennox. They (be) married for ten years. They (live) with their two children on theGreek island off Crete. They (buy) a house on the island in 1987 aand they (live)there since then.B . Jack: since you left school, you (travel) a lot, haven’t you? Jim: Yes, so far I (live) in eight countries, but of course I (visit) more than that. Jack: What is the most interesting place (be) you to? Jim: It’s hard to say. I (be) in Paris a few years ago and i really (enjoy) it. Jack: (you do) a lot of sightseeing while you (be) there? Jim: Yes, I (do). Jack: Where (go) you? Jim: I (go) up the Eiffel Tower, and I (see) a play at the Comedie Francaise. Imust say the play (be) really good. Jack: (ever be) you to the South America? Jim: No, I (not have) the chance to go there yet, but I (hear) a lot about it and Ihope to go there next year.
V. Make sentences with the words provided. Make any changes if necessary.
1.How long/ you/learn English?...............................................................................................................................2.Be/you/Italy?...............................................................................................................................3.Jane/not phone/me/weeks................................................................................................................................4.It/rain/since/I/get up/ this morning................................................................................................................................5.She/be/in hospital/since/Tuesdday...............................................................................................................................
6.We/collect/ stamps/since/we/children................................................................................................................................7.Where/you/ be/since 8 o’clock?...............................................................................................................................8.How long/he/know/you?...............................................................................................................................9.We/not have/holidays/years................................................................................................................................10...........................................................................................................................She/not/cinema/ages................................................................................................................................
1
1 tháng 6 2017
IV. Put in the correct form of the verbs in brackets.
a. Film makers, David Morris (be)HAS BEEN interested in the cinema since he (be) WAS a smallchild. He (make) MADE his first film when he (be)WAS just twelve years old. He is now almost40 and he (make)HAS MADE 30 films. David (love)LOVES travelling. His work (take) TAKES him all over theworld. He (be) HAS BEEN to Africa, India, Australia, China, the Usa and South American. Last year, he (visit) VISITEDRussia for the first time. David (be) WAS married to the singer, LenaLennox. They (be) HAVE married for ten years. They (live) LIVE with their two children on theGreek island off Crete. They (buy)BOUGHT a house on the island in 1987 aand they (live)HAVE LIVED there since then.
B . Jack: since you left school, have you (travel) traveled a lot, haven’t you?
Jim: Yes, so far I (live) have lived in eight countries, but of course I (visit) have visited more than that.
Jack: What is the most interesting place (be) have you been to?
Jim: It’s hard to say. I (be) was in Paris a few years ago and i really (enjoy)enjoyed it.
Jack: (you do) did you do a lot of sightseeing while you (be) were there?
Jim: Yes, I (do)did .
Jack: Where (go) did you go?
Jim: I (go) went up the Eiffel Tower, and I (see) saw a play at the Comedie Francaise. Imust say the play (be)was really good.
Jack: (ever be) have you ever been to the South America?
Jim: No, I (not have) haven't had the chance to go there yet, but I (hear) have heard a lot about it and Ihope to go there next year.
V. Make sentences with the words provided. Make any changes ifnecessary.
1.How long/ you/learn/English?
How long have you learnt English?
2.Be/you/Italy?
Have you been to Italy?
3.Jane/not phone/me/weeks
Jane hasn't phoned me for weeks
4.It/rain/since/I/get up/ this morning
It has been raining since i got up this morning
5.She/be/in hospital/since/Tuesdday
She has been in hospital since Tuesday

6.We/collect/ stamps/since/we/children

We have collected stamps since we were children

7.Where/you/ be/since 8o’clock?

Where have you been since 8 o'clock?

8.How long/he/know/you?

How long has he known you?

9.We/not have/holidays/years

We haven't had holidays for years

.10She/not/cinema/ages

She hasn't been to cinema for ages

Complete the sentences with the appropriate form of the words in brackets. 1. Remind me of my appointment. I am ……………………………. (FORGET) 2. Recently health foods have increased in …………………………... ( POPULAR) 3. Unless something is done about unemployment, the …………………………. for the future is not good. ...
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Complete the sentences with the appropriate form of the words in brackets.

1. Remind me of my appointment. I am ……………………………. (FORGET)

2. Recently health foods have increased in …………………………... ( POPULAR)

3. Unless something is done about unemployment, the …………………………. for the future is not good. ( LOOK)

4. He had been ……………………………… delayed at the office and was now in a hurry to keep his appoinment with the dentist. ( EXPECT)

5. The old lady hid all her …………………………… under the floor ( SAVE)

6. Alison’s …………………………. made it hard for her to speak in public. ( SHY)

7. He had the …………………………….. habit of borrowing books and then forgetting to return them. ( ANNOY)

8. All ………………………………….. must be received before July 20th 2007. ( APPLY )

9. You look rather ………………………………. Are you worried about something? ( OCCUPY)

10. It is much more ………………………………. to buy large size packets. ( ECONOMY )

1
12 tháng 6 2017

Complete the sentences with the appropriate form of the words in brackets.

1. Remind me of my appointment. I am ……………………forgetful………. (FORGET)

2. Recently health foods have increased in ………………popularity…………... ( POPULAR)

3. Unless something is done about unemployment, the ……………outlook……………. for the future is not good. ( LOOK)

4. He had been ………………uexpectedly……………… delayed at the office and was now in a hurry to keep his appoinment with the dentist. ( EXPECT)

5. The old lady hid all her …………savings………………… under the floor ( SAVE)

6. Alison’s ………………shyness…………. made it hard for her to speak in public. ( SHY)

7. He had the ……………annoyed……………….. habit of borrowing books and then forgetting to return them. ( ANNOY)

8. All ………………applications………………….. must be received before July 20th 2007. ( APPLY )

9. You look rather ………prepccupied………………………. Are you worried about something? ( OCCUPY)

10. It is much more …………economical……………………. to buy large size packets. ( ECONOMY )

1. A. thirstyB. guitarC. dirtyD. listen2. A. openedB. playedC. wickedD. cleaned3. A. dislikeB. designC. musicD.light4. A. proudB. aboutC. aroundD. would5. A. booksB. dogsC. catsD. mapsPART B: GRAMMAR &VOCABULARYI.    Choose the best option to complete each of the following questions. (15questions)6.   We              in that flat since we got married.A. have livedB. have liveC. has livedD. has live7.   - Mitchel: “ Online learning seems the best solution now?”- Laura: “...
Đọc tiếp

1. A. thirsty

B. guitar

C. dirty

D. listen

2. A. opened

B. played

C. wicked

D. cleaned

3. A. dislike

B. design

C. music

D.light

4. A. proud

B. about

C. around

D. would

5. A. books

B. dogs

C. cats

D. maps

PART B: GRAMMAR &VOCABULARY

I.    Choose the best option to complete each of the following questions. (15questions)

6.   We              in that flat since we got married.

A. have lived

B. have live

C. has lived

D. has live

7.   - Mitchel: “ Online learning seems the best solution now?”

- Laura:           _. It helps students keep learning while schools are closed”

A. I quite agree                                                              B. Well, that’s very surprising

C. Of course not. You bet!                                          D. I don’t think that’s a good idea

8.   Mr Ba ……………. a good holiday last year.

A.made

B.passed

C.had

D.spend

9.     Some designers have taken............................... from Vietnam’s ethnic minorites.

A. inspiration

B. comparison

C. experiment

D. communication

10.     They said they......... there the next day.

A. go

B. went

C. will go

D. would go

11.     Everyone likes English,….............. ?

A. does it

B. is it

C. will they

D. don’t they

12.     My father asked us.............. too much time playing computer games.

A. not to spending

B. did not spend

C. not to spend

D. to not spent spending

13.   Mount Pinatubo,................. s a volcano in the Philippines, erupted in1991.

A. who

B. which

C. where

D. whose

14.   Its design tells that the house............... in the late 1990s.

A. built

B. had built

C. was built

D. had been built

15.   Susan studied very well,___________ she could pass the exam easily.

A. if

B. so

C. but

D. or

16.   She didn’t enjoy her first year at high school because she failed to             her new friends.

A. get on with

B. come up with

C. look at

D. look through

17.................................. the traffic was bad , we arrived on time.

A. In spite of

B. Because

C. Although

D. Despite

18.   The men ........... dinner when the phone……… .

A. were having/ was ringing

B. had/ rang

 

 

 

 

C. had/was ring

D. were having/ rang

19.   Maryam and Lan are pen pals and they................... at least once a month.

A. correspond

B. visit

C. meet

D. exchange

20.   He has been very interested in doing research on...... since he was at secondary school

A. biological

B. biology

C. biologist

D. biologically

 help me cần gấp

2
17 tháng 11 2021

mik chỉ biết vài câu thui

1 b

3b \

sorry vì chỉ ít nha huhu

17 tháng 11 2021

1.B

2.C

3.D

4.D

5.B

6.A

7.B

8.C

9.A

10.C

11.B

12.B

13.C

14.B

15.B

16.A

17.C

18.D

19.C

20.A

Nếu sai thì mong chị thông cảm chứ em mới học lớp 6 thôi!!! Nhưng em được học nhiều về môn tiếng anh rồi, mong chị k