Cho đường tròn tâm O đường kính AB và S là một điểm nằm bên ngoài đường tròn SA và SB lần lượt cắt đường tròn tại M, N gọi H là giao điểm của BM và AN chứng minh rằng SH vuông góc với AB

Các câu hỏi liên quan

1. Look! A man ( run) ……………………….after the train. He ( want) ……………………….. to catch it. 2. What you ( do) …………………………..now? 3. Where Ann ( be) ………………………….. at present? 4. Mary usually ( wear) ……………… a blue dress, but now she ( wear) ………………….. a flowered one. 5. In the South Vietnam, it ( rain) …….. a great in July, August, and September. Now it ( rain) ...........…..outside. 6. Where Mr. Buck ( live) ………………..now? He ( live) ……………..with his daughter for six months every year. 7. It ( be) …………………………..very cold now. 8. She( feel) ………………………….. tired at the moment. 9. Yes, I ( remember) …………………………..that older fellow’s name now. 10. He often ……………………………. (go) to school on foot. 11. It …………………………….(rain) very hard now. 12. The sun ……………………….(warm) the air and …………………………….(give) us light. 13. Look! A man …………………………….(run) after the train. 14. She ……………………….(go) to school everyday. 15. Bad students never ……………………….(work) hard. 16. It often ……………………….(rain) in the summer. It ……………………….(rain) now. 17. The teacher always …………. (point) at the black – board when he ………. (want) to explain something. 18. Mother …….(cook) some food in the kitchen at the moment, she always ………….(cook) in the morning. 19. I always ……………………….(meet) him on the corner of this street. 20. Where …………. you …...………..(go) now? – I ……………………….(go) to the theater. 21. He ……………………….(not do) morning exercises regularly. 22. ………………… he ……………………….(do) morning exercises now? 23. Water ……………………….(boil) at 100 degrees centigrade. 24. He ………………….. (meet) the dentist next week. 25. …………………. you ……………………..(be) a good student? 26. They …………….. usually …………………. (not go) to school by motorbike. 27. He …………………………… (swim) overthere now. 28. She ……………………..(come) here next month. 29. They ……………………….. (not be) doctors. 30. He often ……………………………… (get) up late.