Cho tam giác ABC có góc B = góc C, kẻ AH vuông gốc với BC, H thuộc BC. Trên tia đối của tia BC lấy điểm D, trên tia đối của tia CB lấy điểm E sao cho BD = CE. Chứng minh:
a) AB = AC
b) tam giác ABD = tam giác ACE
c) tam giác ACD = tam giác ABE
d) AH là tia phân giác của góc DAE
e) kẻ BK vuông góc AD, CI vuông góc với AE. Chứng minh ba đường thẳng AH,BK,CI cùng đi qua một điểm.
=666
stubit
Viết câu tương đương:
1/ What about going to the movies?
→ Why........................................................
2/ Where does she live?
→ What........................................................
3/ What do you do?
→ What........................................................
4/ The dress is very old.
→ What......................................................!
5/ What subject does she like best?
→ What is......................................................
6/ How much is the hat?
→ How much does.............................................?
7/ Lan is taller than Hoa.
→ Hoa is......................................................
8. No one in the group is taller than Trung.
→ Trung......................................................
9. I get to work in half an hour.
→ It takes.....................................................
10/ Nam works more hours than lan.
→ Lan works...............................................
11/ We have a two-month summer vacation.
→ Our summer vacation lasts.....................
12/ Vietnamese students have fewer vacations than American ones.
→ American students..................................
13/ It takes me about two hours each day to do my homework.
→ I spend...................................................
14/ How much are these rackets?
→ how much do.........................................
15/ do you enjoy listening to music?
→ Are.........................................................
16/ there is a sick, a tud and a showerin the bathroom.
→ The bathroom........................................
17/ No one in the group is taller than Trung.
→ Trung....................................................
18/ I get to work in half an hour.
→ It takes.................................................
19/ How much is this dictionary?
→ How much does..................................
20/ How about eating out tonight in restaurant?
→ Why don't we.....................................