Cho tam giác ABC vuông tại A có AB < AC. Vẽ AH vuông BC tại H. Vẽ HI vuông AB tại I. Trên tia HI lấy D sao cho I là trung điểm của DH.
a) Chứng minh tam giác ADI = tam giác AHI
b) Chứng minh AD vuông góc BD
c) Cho BH = 9 và HC = 16. Tính AH
d) Vẽ HK vuông góc AC tại K và trên tia HK lấy điểm E sao cho K là trung điểm của HE. Chứng minh DE < BD + CE

Cho tam giác ABC có ba góc nhọn. Gọi D là trung điểm của BC. Trên tia AD lấy điểm E sao cho DE=DA (E khác A)

a/ Chứng minh: \(\Delta\)ADB =\(\Delta\)EDC

b/Chứng minh: góc ABD= góc ECD

c/Qua D kẻ đường thẳng vuông góc với BE tại M (M\(\in\)BE) và cắt AC tại N (N\(\in\)AC). Chứng minh: MN vuông góc AC

Giải giúp mình câu này với thank nhiều

B1

1 We re very worried .....apending lots of money on energy in our home

A about b with c to d on

2 ill be in trouble if I ....my passport

A lose b will lose c lost d would lose

3 what was wrong...you yesterday ?- i had a cold

A for b to c lost d about

B2 viết phiên âm ra và khoanh

1 a architect b church c children d armchair

2 a general b garden c go d get

3 a cancel b ceilling c calling d cupboard

4 a calorie b carve c collage d centre

V. Choose the underlined part A, B, C  or D which need correcting.

1.  I am very please that we should meet again soon.

         A               B         C           D

2. Peter introduced Mai with some of his friends in London.

   A            B    C                   D

3. The police stopped everybody enter the house.

      A            B   C   D

4. The pilot and the crew divided the life preserves between twenty frantic passengers.

  A     B C        D

5. Standing among so many strangers, the frightened child began to sob uncontrollable.

          A B       C             D

6. Tom keeps to study hard because he intends to go to dental school.

            A               B         C                D

7. When the bell rang, the students have left the class.

              A       B                               C            D

8. The government has decided voting on the resolution now rather than next month.

  A                    B                 C                        D

9. I don’t recommend to eat in that restaurant. Its food is awful.

                     A               B         C     D

10. One of the primary cause of road accidents is driving after drinking.

        A                             B                  C        D

Exercise 3: Find the incorrect part  A, B, C and D.( sửa giúp mình nhé)

1. Each of the rooms have its own bathroom.

             A           B       C    D

2. Everybody who have  a fever must go home immediately

                        A      B                   C                          D

3. Twenty five dollars  are  all I can afford to pay for this recorder

                           A         B                     C        D

4. All of the windows in my house was broken in  the  earthquake.

        A                          B                  C                     D

5. The actress, along with her manager and some friends, are going to the party.

                                           A                               B              C             D

6. Living  expenses  in  this country  are high.

        A            B         C                       D

VI. Choose the underlined part (marked A, B, C or D) that contains an error

1.  I haven’t heard from Maria since a long time.

               A                B                   C      D

2.  Nam has not finished his homework yesterday.

       A              B                C         D

3. Although he was tired, but he still went to work last week.

                           A             B                C         D

4. She wanted to know how long did it take to get there.

              A                         B          C                     D