user-avatar
lien.long345
2 năm trước
Gọi O là trung điểm của đoạn thẳng AB. Trên cùng một nửa mặt phẳng bờ là đường thẳng AB, kẻ hai tia Ax, By cùng vuông góc với AB. Trên tia Ax lấy điểm C ( C khác A ) . Từ O kẻ đường thẳng vuông góc với OC và cắt By tại D. Từ O hạ đường vuông góc CM xuống CD ( M thuộc CD ) a, CM: OA ²= AC.BD b, CM: ΔAMB vuông c, Gọi N là giao điểm của BC và AD. CM: MN//AC OA ²
Thích Trả lời Chia sẻ

Các câu hỏi liên quan

26. Mark the letter A, B, C or D on your answer sheet to indicate the word that differs from the other three in the position of primary stress in each of the following questions. A:worship B:enjoy C:belong D:behave Question15. The Thai worship their ancestors. Every year they hold festivals and ceremonies with alternating songs between boys and girls, and many traditional games. A:grandfathers B:forefathers C:grandparents D:fathers Question 22. I only remembered we had a meeting when you called me. A:You always phone me to remind me of when our meeting is. B:As soon as I realized that we had a meeting, you called me. C:I didn’t remember about our meeting until you called. D:I was happy because you remembered to call me for the meeting. 30.Mark the letter A, B, C or D on your answer sheet to indicate the word whose underlined part differs from the other three in pronunciation in each of the following questions . A:generous B:princess C:cinema D:comedy Question8. Don’t worry. It is _______ to travel to that village even at night. A:difficult B:inconvenient C:unsafe D:safe Question 24. While I sympathize with your problem, there is nothing I can do to help. A:I can’t do anything for you, though I understand what you are going through. B:Perhaps I can help you if you tell me more about your problem. C:I would like to help you sort out this problem, but I won’t. D:Since I have no idea about your problem, I cannot be of any assistance. Question9. Yoga helps us learn _______ to co-ordinate breathing and movement. A:what B:when C:why D:how

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