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+ ΔAHB và ΔCKD có
HB = KD (=1)
góc AHB = góc CKD(=90º)
AH = CK (=3).
⇒ ΔAHB = ΔCKD(c.g.c)
⇒AB = CD (hai cạnh tương ứng)
+ ΔCEB và ΔAFD có
BE = DF (=2)
góc BEC = góc DFA (=90º)
CE = AF (=4).
⇒ ΔCEB = ΔAFD ( c.g.c)
⇒ BC = AD (hai cạnh tương ứng)
b) ΔABD và ΔCDB có
AB = CD
AD = BC
BD cạnh chung
⇒ ΔABD = ΔCDB (c.c.c)
⇒ góc ABD = góc CDB (hai góc tương ứng)
Vậy AB // CD ( hai gó so le trong bằng nhau )
k minh nha
A B C D E F M N
(hình hơi xấu, thông cảm nha)
a) Xét \(\Delta AEB\)và \(\Delta DFC\) có:
AE = DF
\(\widehat{AEB}=\widehat{DFC}=90^o\)
BE = CF
Do đó: \(\Delta AEB=\Delta DFC\) (c.g.c)
Suy ra: AB = DC (đpcm)
Xét \(\Delta BMC\) và \(\Delta DNA\) có:
MC = NA
\(\widehat{BMC}=\widehat{DNA}=90^o\)
BM = DN
Do đó: \(\Delta BMC=\Delta DNA\)
Suy ra: BC = AD (đpcm)
b) Xét \(\Delta ABD\) và \(\Delta CDB\) có:
AB = CD (câu a)
BC = AD (câu a)
BD là cạnh chung
Do đó: \(\Delta ABD=\Delta CDB\) (c.c.c)
Suy ra: \(\widehat{ABD}=\widehat{CDB}\) (so le trong)
=> AB // CD (đpcm)
3/2:Feberury the third
20/11:November the twentieth
30/4:April the thirtieth
22/12:December the twenty-second
2/9:September the second
26/3:Match the twenty-sixth
19/8:August the nineteenth
10/10:October the tenth
7/5:May the seventh
27/7:July the twenty-seventh
1. 3/2............the third of Febulary............
2. 20/11............the.twentyth of November............
3. 30/4...........the thirty of April..................
4. 22/12......the twenty - second of December............
5. 2/9...........the second of September.................
6. 26/3.........the twenty- sixth of March.............
7. 19/8........the nineteenth of August........
8. 10/10........the tenth of October..........
9. 7/5 ............the seventh of May............
10. 27/7.................the twenty-seventh of July....................
1. 3/2 ..............the third of February.................
2. 20/11 ......the twentieth of November..................
3. 30/4 ..........the thirtieth of April...............
4. 22/12 ..the twenty second of December..............
5. 2/9 .........the second of September................
6. 26/3 ........the twenty sixth of March...............
7. 19/8 ............the nineteenth of August.................
8. 10/10 .........the tenth of October...................
9. 7/5 ...........the seventh of May..................
10. 27/7 .........the twenty seventh of July................
Em hãy viết theo cách đọc những ngày tháng sau.
Ví dụ: 1/1: the first of January
1. 3/2 : The third of February .
2. 20/11 : The twentith - two of November .
3. 30/4 : The thirtith of April .
4. 22/12 : The twentith - two of December .
5. 2/9 : The second of September .
6. 26/3 : The twentith of March
7. 19/8 : The nineteenth of August
8. 10/10 : The tenth of October .
9. 7/5 : The seventh of May
10. 27/7 : The twentith - seven of July.
1. will make
2. is sleeping
3. goes
4. stayed
5. has spoken
6. will not go
7. are flying
8. are
9. wnt
10. brushes
1.Does he often work many hours a week?
2.American students do not usually wear school uniform.
3.Nam has Science class at 10:00 on Wednesda.
4.What subject does Tom best?
5.You want to work with me
6.How do you know ke s meat?
7.Excuse me! Is a post office near here?
8.That is the letter,Is Mai want to post?
9.I will tell after 5 call him again.
1.?
2. There ..are.. 45 students in my class .
3. Look ! The cat ..is sleeping..
4. ..Do.. you ..usually listen... to music ?
5. What ...is.. he ..doing.. at the moment ? - He ...is using.. his computer .
6. My father ..s.. watching TV .
7. ..Do.. they ..visit.. their hometown every day ?
8. She ..gets.. up at 6 o'clock in the morning ?
1. never
2 . are
3 . is sleeping
4 . Do ........usually listen
5 . is ........doing / is using
6 . s
7 . Do ........visit
8 . gets
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