cho tam giác nhọn ABC , đường tròn đường kính BC cắt các cạnh AB, AC lần lượt tại D,E . Gọi H là giao điểm của BE và CD
a, chứng minh ADHE nội tiếp đường tròn
b, Gọi K là giao điểm của đường thẳng BC với đường thẳng AH . chứng minh ΔBHK đồng dạng Δ ACK
c,chứng minh rằng KD+KE < hoặc = BC. dấu "= " xảy ra khi nào?
các bạn giúp minh nhé câu c thôi ạ . cảm ơn
bài tập về mệnh đề quan hệ
1. thu want to drink some medicine. she had a headache
2. Lan went back home . Her child was seriously ill after the rain
3. Mr tuan is very tall and thin. He is our gym master
4. The lady in black is a famous writer. You met her at the party last night
5. The little boy lost his way. He is crying over there
các bạn giúp mình nhé mình cảm ơn
hoàn thành câu :
1.my daughter/ eager/ go/London/friends
2. he/ happy/ meet/old friends/again
3.sister /told/ him / buy/ present/ mother/ birthday
4 .it/ rain / when/ i/ got up/ morning
5.you/ want /me /bring / something/ camping/ tomorrow /?
6. floor / need / clean/ because/ that
7.Mary / always/take/ care / English books
8. before / go/ cinema/he/ learn /lesson/ carefully
9. I/advise/ you/ not/ behave/ that
10. Hamlet/ write/ Shakespeare
11. books/ arrange/ different sections/ Mrs. Green
12. library cards/ give/ readers/ beginning/ school year
13.each reader/ want /borrow/ books/ must / library/ card
14 . picture books/ can/ find/ shelves/against/ wall
15.how/ we / make/ book/ more interesting/?
16 they/ make/ him/ promise/ not/ do/ it/ again
17. you/think/morning exercises / make/ us/ stronger/?
18 . unless / study hard / fail/ exam
19. Ha Long Bay / beautiful sport/I/ want /visit
20. wish /we /have/ fresh air
21. what language/ speak/Canada
22. he / wish / get/ bad marks
23. I/not see/ Lan/ two weeks
24 how long/ you/ wait / result / exam ?
25 . he/ not/ intelligent/ understand /you/say
mong các bạn giúp mình. thanks