2 walking outdoor is fun

3 How high was Ba last year?

4 Hoa doesn't like coffee and neither does Ba

5 My father drive carefully

6 What bout going to the cafeteria for a cold drink

7 Hoan is good at playing tennis

8 It is interesting to go fishing with friends at weekends

Var i,n:integer;

p:longint;

Begin

Write('Nhap n = ');readln(n);

p:=0;

For i:=2 to n do p:=p*i;

Write('Tich la ',p);

Readln;

End.

Var i,n:integer;

p:longint;

Begin

Write('Nhap n = ');readln(n);

p:=1;

For i:=2 to n do p:=p*i;

Write('Tich la ',p);

Readln;

End.

Cm:Xét tứ tứ giác AEBH có: EM = MH (gt); AM = MB (gt)

                              \(\widehat{AHB}=90^0\)

=> tứ giác AEBH là hình chữ nhật

=> AE // BH hay AE // BC

b) Xét t/giác ABC cân tại A có AH là đường cao

=> AH cũng là đường trung tuyến

=> BH = HC

Ta có: AEBH là hình chữ nhật => AE = BH

            mà BH = HC (cmt)

=> AE = HC

Xét tứ giác ACHE có AE // HC (cmt)

      AE = HC (cmt)

=> ACHE là hình bình hành

c)  Để hình chữ nhật AHBE là hình vuông

<=> AH = HB 

<=> t/giác AHB là t/giác vuông cân

<=> \(\widehat{BAH}=45^0\)

<=> \(\widehat{A}=90^0\) (Do t/giác ABC cân có AH là đường cao => AH là đường trung tuyến)

<=> t/giác ABC vuông cân

Vậy ...

1. I am not tall enough to reach the ceiling

2. She is sociable enough to make friends easily

3. He is looking at himself in the mirror at the moment 

4. I have to stop smoking

5. Mr. Kerry used to run 5 miles every morning when he was a teenager

6. We really like her sense of humor

7. He ought not to play computer games

8. Hilary doesn't hace to wear uniform at school

1. I am not tall enough to reach the ceiling

2. She is sociable enough to make friends easily

3. He is looking at himself in the mirror at the moment 

4. I have to stop smoking

5. Mr. Kerry used to run 5 miles every morning when he was a teenager

6. We really like her sense of humor

7. He ought not to play computer games

8. Hilary doesn't hace to wear uniform at school

AH = BC => tam giác MBC =MHA ( tự cm)

=> BMH vuông cân tại M => NBA = BAN = 45

=>...