Cho tam giác abc vuông tại a có AB = 6cm, AC = 8cm. Vẽ đường cao AH

a) Chứng minh: AC²=CH.BC

b) Tính BC và CH

c) Từ H kẻ đường thẳng vuông góc với AB và cắt AB tại D. tính diện tích tứ giác ADHC

Exericise 2. Hãy chọn từ có phần được gạch dưới có cách phát âm khác với các từ còn lại:

1. A. failed B. reached C. absorbed D. solved

2. A. invited B. attended C. celebrated D. displayed

3. A. removed B. washed C. hoped D. missed

4. A. looked B. laughed C. moved D. stepped

5. A. wanted B. parked C. stopped D. watched

6. A. laughed B. passed C. suggested D. placed

7. A. believed B. prepared C. involved D. liked

8. A. lifted B. lasted C. happened D. decided

9. A. collected B. changed C. formed D. viewed

10. A. walked B. entertained C. reached D. looked

11. A. watched B. stopped C. pushed D. improved

12. A. admired B. looked C. missed D. hoped

13. A. proved B. changed C. pointed D. played

14. A. helped B. laughed C. cooked D. intended

15. A. smoked B. followed C. titled D. implied

16. A. coughed B. phoned C. booked D. stopped

17. A. talked B. looked C. naked D. worked

18. A. developed B. ignored C. laughed D. washed

19. A. phoned B. stated C. mended D. old-aged

20. A. clapped B. attracted C. lifted D. needed

21. A. involved B. believed C. praised D. locked

22. A. remembered B. cooked C. closed D. cleaneD

23. A. smiled B. regarded C. suggested D. naked

24. A. reversed B. choked C. played D. sentenced

25. A. minded B. hated C. exchanged D. old-aged

26. A. proved B. looked C. stopped D. coughed

27. A. dated B. changed C. struggled D. agreed

28. A. scaled B. stared C. phoned D. hundred

29. A. behaved B. washed C. clicked D. approached

30. A. worked B. shopped C. missed D. displayed

31. A. coughed B. cooked C. melted D. mixed

32. A. signed B. profited C. attracted D. naked

33. A. walked B. hundred C. fixed D. coughed

34. A. watched B. practiced C. introduced D. cleaned

35. A. passed B. stretched C. comprised D. washed

36. A. tested B. clapped C. planted D. demanded

37. A. intended B. engaged C. phoned D. enabled

38. A. married B. sniffed C. booked D. coughed

39. A. smiled B. denied C. divorced D. agreed

40. A. planned B. developed C. valued D. recognized

41. A. approved B. answered C. passed D. uttered

42. A. doubted B. wedded C. connected D. passed

43. A. managed B. laughed C. captured D. signed

44. A. washed B. exchanged C. experienced D. mixed

45. A. filled B. added C. started D. intended

46. A. wanted B. booked C. stopped D. laughed

47. A. booked B. watched C. jogged D. developed

48. A. kneeled B. bowed C. implied D. compressed

49. A. bottled B. explained C. trapped D. betrayed

50. A. laughed B. stamped C. booked D. contented