user-avatar
sonbean3011
2 năm trước
Từ điểm E nằm bên ngoài đường tròn ( O;R ) ( OE < 2R ) , vẽ tiếp tuyến EA , EB ( A,B là 2 tiếp điểm ) .Lấy M là trung điểm của BE .Kẻ AM cắt ( O ) ở N .Gọi H là giao điểm của AB với OE . Kẻ cát tuyến ENI với đường tròn O a) Cm : $\widehat {BNM}$ = $\widehat {ABE}$ và Tứ giác HNMB nội tiếp . b) Cm : AI // BE c) Cho $\widehat {AEB}$ = 120° . Tính $\frac{S_{ABI}}{S_{ABE}}$
Thích Trả lời Chia sẻ

Các câu hỏi liên quan

MIXED EXERCISES * Exercise 1: Choose the best answer to complete each of the following sentences. 1. I learned that the college ________ in 1900. A. found B. was founded C. founded D. had been founded 2. After he.......................his English course, he went to England to continue his study. A. has finish B. had finished C. was finished D. would finish 3. How.........................since we .....................college? A. are you- left B. were you- left C. have you been- have left D. have you been- left 4. I..................you lately. We..........................three months ago. A. haven’t seen- last met B. didn’t see- met C. haven’t seen- have meet D. didn’t see- have met 5. The Chinese...............spaghetti dishes for a long time before Marco Polo............. back to Italy.. A. made- brought B. have made- brought C. made- had brought D. had been making- brought 6. When I arrived at the meeting the first speaker.................speaking and the audience................... A. just finished- were clapping B. had just finished- had clapped C. had just finished- were clapping D. just finished- had clapped 7. He.............................his job last month and then he..................out of work. A. lost- was B. was lost- had been C. has lost- was D. lost- has been 8. In the last hundred years, travelling.......................much easier and more comfortable. A. become B. has become C. became D. will became 9. He _____ in Quang Ngai before I moved to Binh Thuan. A. has been living B. has lived C. had lived D. was living 10. In the past, the trip...................very rough and often dangerous, but things..........a great deal in the last hundred and fifty years. A. was- have changed B. is- change C. had been- will change D. has been- changed 11. She................ to Hanoi for her summer vacation last year. A. went B. go C. goes D. is going 12. The train ______ half an hour ago. A. has been leaving B. left C. has left D. had left 13. When Carol....................last night, I................my favorite show on television. A. was calling- watched B. called- have watched C. called- was watching D. had called- watched 14. By the time next summer, you....................your studies. A. completes B. will complete C. are completing D. will have completed 15. By Christmas, I _______ for Mr. Smith for six years. A. will have been working B. will work C. have been working D. will be working

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