user-avatar
hoangphucng270
2 năm trước
Bài 4. (3,5đ) Cho đường tròn (O), điểm M nằm ngoài đường tròn. Vẽ tiếp tuyến MA tới đường tròn (A là tiếp điểm). Gọi E là trung điểm của đoạn AM và I, H theo thứ tự là hình chiếu của E và A xuống OM. Qua M vẽ cát tuyến MBC tới (O) (MB < MC) và tia MC ở giữa hai tia MO và MA. 1) Chứng minh hai tam giác MBH và MOC đồng dạng. từ đó suy ra tứ giác BCOH nội tiếp. 2) Chứng minh AHB  AHC. 3) Vẽ tiếp tuyến IK tới (O). Chứng minh tam giác MKH vuông. 4) Cho BC = 3BM và D là trung điểm đoạn MC. Chứng minh MC là tiếp tuyến của đường tròn ngoại tiếp tam giác ODH.
Thích Trả lời Chia sẻ

Các câu hỏi liên quan

Exercise 4: Choose the best option to fill in the blank. 1. In 1939, this ..................... was made to tell stories about the real life of Abraham Lincoln as a young man. A. biopic B. science fiction film C. action film D. horror film 2. When watching that ....................., we can’t help laughing at the stupid things of the main actor. A. documentary B. comedy C. action film D. horror film 3. My son feels very happy when he sees that ..................... with a lot of cute animals. A. horror film B. biopic C. thriller film D. animation 4. Most ..................... say that this film is worth watching. A. plots B. settings C. critics D. acting 5. He acts very well. I’m sure that yesterday he stayed up all night reading the ............... A. acting B. character C. survey D. script 6. Before you go to the cinema, you can watch the trailer and read .............. of the film. A. reviews B. disaster C. critic D. character 7. That was a ................ and boring horror film so I slept from the beginning to the end. A. shocking B. entertaining C. gripping D. predictable 8. I didn’t expect the movie to be so interesting and so .....................! I cried at the end of the film. A. moving B. violent C. confusing D. hilarious 9. According to our latest survey, Batman is one of 10 ..................... films this summer. A. must-see B. violence C. embarrassed D. stunt 10. Woody Allen is one of some directors who ..................... in their own films and receive positive reviews. A. set B. star C. recommend D. make 11. The film had such a sudden and ..................... ending that no one can imagine. A. disappointed B. must-see C. predictable D. shocking 12. Watching ..................... films may make people more aggressive. A. hilarious B. violent C. entertaining D. gripping Exercise 5: Complete the sentences with although, in spite of/despite. 1. ............................. the weather was bad, we enjoyed our trip. 2. The children slept well ............................. the noise. 3. ............................. earning a low salary, Linda gave money to her parents. 4. John rarely sees Paul ............................. they live in the same town. 5. Julie failed the exam ............................. of working very hard. 6. ............................. it was cold, she didn’t put on her coat. 7. Tom went to work ............................. not feeling very well. 8. Anna never learned the language ............................. she lived there for two years. 9. ............................. the difficulty, they managed to climb to the top of the mountain. 10. I couldn’t eat ............................. I was very hungry. Exercise 6: Underline the correct answers. 1. He’s such a monotonous speaker. I was bored/ boring stiff. 2. Most sequels are disappointed/ disappointing. 3. I had such a tired/ tiring day I went straight to bed. 4. Everyone’s very excited/ exciting about the news. 5. That lamp produces a very pleased/ pleasing effect. 6. The whole school was saddened/ saddening by the tragic event. 7. I don’t like watching depressed/ depressing films on my own. 8. I was amazed/ amazing when she toid me she’d got divorced. 9. He’s such a bored/ boring guy. He only ever talks about himself. 10. I’m very interested/ interesting in films and theatre. 11. No one knew what would happen next. We were all intrigued/ intriguing. 12. It was a very interested/ interesting situation. 13. There’s been some very surprised/ surprising news. 14. His mother was disgusted/ disgusting by what she found under her bed. 15. Their hamburgers are disgusted/ disgusting. 16. Dad always arrives home from work thoroughly exhausted/ exhausting. 17. He’s always showing off. It’s really annoyed/ annoying. 18. I think Alex is one of the most annoyed/ annoying people I’ve ever met. He can’t keep still for a second. 19. I walked into this restaurant and there was Andy with a strange woman. He seemed really embarrassed/ embarrassing. 20. She kept talking about her boyfriend problems all night. It was rather embarrassed/ embarrassing.

2018 © Loga - Không Ngừng Sáng Tạo - Bùng Cháy Đam Mê
Loga Team