Bài 1 Cho tam giác ABC vuông tại A, có và AB = 5cm. Tia phân giác của góc B cắt AC tại D. Kẻ DE vuông góc với BC tại E. 1/ Chứng minh: ABD = EBD. 2/ Chứng minh: ABE là tam giác đều. 3/ Tính độ dài cạnh BC. Bài 2. Tam giác có độ dài ba cạnh sau có phải là tam giác vuông không? Vì sao? a) 3cm, 4cm, 5cm; b) 4cm, 5cm, 6cm. Bài 3. Cho tam giác ABC có số đo các góc A, B, C tỉ lệ với 3; 2; 1. a) Tính số đo các góc của tam giác ABC. b) Lấy D là trung điểm của AC, kẻ DM  AC (M  BC). Chứng minh rằng tam giác ABM là tam giác đều. Bài 4. Cho tam giác ABC, điểm D thuộc cạnh BC ( D không trùng với B; C). Lấy M là trung điểm của AD. Trên tia đối của tia MB lấy điểm E sao cho ME = MB. Trên tia đối của tia MC lấy điểm F sao cho MF = MC. Chứng minh rằng: a) AE // BC; b) Điểm A nằm giữa hai điểm D và E. Bài 5 Cho Ot là tia phân giác của góc ( là góc nhọn) . Lấy điểm M Ot, vẽ MA Ox , MB Oy (A Ox, B Oy ) 1/ Chứng minh: MA = MB . . 2/ Cho OA = 8 cm; OM =10 cm. Tính độ dài MA. 3/ Tia OM cắt AB tại I . Chứng minh : OM là đường trung trực của đoạn thẳng AB Bài 6. Cho tam giác ABC vuông tại A, có và AB = 5cm. Tia phân giác của góc B cắt AC tại D. Kẻ DE vuông góc với BC tại E. 1/ Chứng minh: ABD = EBD. 2/ Chứng minh: ABE là tam giác đều. 3/ Tính độ dài cạnh BC. Bài 7. Cho tam giác ABC và tam giác A’B’C’ có , AB=A’B’, AC=A’C’. M là trung điểm của BC. Chứng minh AM=1/2 B’C’

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* Finish each of the following sentences in such a way that it means exactly the same as the sentences printed before it. 1. The trains couldn’t run because of the snow. ⇒ The snow .. 2. I didn’t arrive in time to see her. ⇒ I wasn’t early ..... 3. I’m sorry I was rude to you yesterday. ⇒ I apologize ..... 4. He didn’t hurry, so he missed the train. ⇒ If ...... 5. Janet is the best tennis- player in the club. ⇒ No one ....... 6. I haven’t seen that man here before. ⇒ It’s ......... 7. The furniture was so expensive that I didn’t buy it. ⇒ The furniture was too ......... 8. The robbers made the bank manager hand over the money. ⇒ The bank manger ......... 9. He learned to drive when he was 18. ⇒ He has ................................................................................................ 10. She had never been unhappy before. ⇒ She was unhappier ................... 11. It was so late that nothing could be done. ⇒ It was too .......... 12. I asked the hotel porter to wake me at 8 o’clock the following morning. ⇒ “ Please ......... 13. They’ll have to change the date of the meeting again. ⇒ The date ...... 14. The garage is going to repair the car for us next week. ⇒ We are going ............ 15. The bus takes longer than the train. ⇒ The train .............. 16. John has not had his hair cut for over six months. ⇒ It’s ............ 17. Maria says she’ll like to have been put in a high class. ⇒ Maria wishes ....... 18. Would you like me to finish the work tonight? ⇒ I’ll .... 19. You may get hungry on the train, so take some sandwiches. ⇒ In ..... 20. My husband didn’t leave the car keys, so I couldn’t pick him up at the station. ⇒ If my husband .............. 21. “I don’t think John will come,” said Bill. ⇒ Bill doubted ..... 22. The postman was bitten by our dog. ⇒ Our dog .......... 23. We couldn’t drive because of the fog. ⇒ The fog prevented ........ 24. Although his leg was broken he managed to get out of the car. ⇒ In spite .. 25. The cake was so hard that I could not eat it. ⇒ It was ... 26. We didn’t go because it rained. ⇒ If it hadn’t ... 27. I can’t cook as well as my mother does. ⇒ My mother ......... 28. I don’t suppose you have change for a pound, do you? ⇒ Do you happen ........ 29. He failed to win the race. ⇒ He didn’t ..... 30. Mary rang hours and hours ago. ⇒ It’s hours ...... 31. I’m sorry that I didn’t finish my homework last night. ⇒ I wish .......... 32. She asked John how he liked her new dress. ⇒ “How....... 33. A train leaves at eight o’clock every morning. ⇒ There is ............ 34. Nobody can deny that she has a beautiful voice. ⇒ It ...... 35. I would like you to help me to put the chairs away. ⇒ Do you mind ......... 36. The child will die if nobody sends for a doctor. ⇒Unless ....... 37. He would prefer you to pay him immediately. ⇒ He’d rather ............ 38. The water was so cold that the children could not swim in it. ⇒ The water was not ........ 39. Somebody repaired her car yesterday. ⇒ She .... 40. You must see the manger tomorrow morning. ⇒ You’ve ....... 41. There was never any answer when we rang. ⇒ Every ......... 42. That’s an insulting name to use for him. ⇒ Don’t call ........ 43. John asked if it was the blue one or the green she wanted. ⇒ “Which .... 44. She liked Paris very little, and Rome less. ⇒ She thought Rome ....... 45. I can meet you if you arrive before eleven. ⇒So ..... 46. They will catch all the prisoners again by tonight. ⇒ All the prisoners ........ 47. I’ve warned you not to go near that dog. ⇒ I’ve warned you about ..... 48. No, please don’t tell him. ⇒ I’d rather ......... 49. Why don’t you ask her yourself? ⇒ I suggest ......... 50. An up- to- dated visa is necessary for Andorra. ⇒ You’ll .....