user-avatar
216864356629016
2 năm trước
Cho tam giác ABC, M là trung điểm của AC, D là điểm đối xứng với B qua M .Qua C vẽ đường thẳng d cắt AB. Gọi A',B' và D' lần lượt là hình chiếu của A,B và D trên đường thẳng d. CMR: DD'=AA'+BB'
Thích Trả lời Chia sẻ

Các câu hỏi liên quan

1) Complete the short conversation with the word, in the box. Then practise them with a partner. 1) A : Does your________________hurt ? B : Yes, I ran into a tree. 2) A : What's the matter? B : I_________________my toe in the game yesterday. 3) A : Why are you walking like that ? B : I________________my ankle when I was jogging. 4) A : Where are you going ? B : To the dentist's. I have__________________ 2) Complete the conversation with the phrases in the box. Then answer the questions below. It will cost you With a bit of luck I hate to say this I can't wait David : This is great. (1)_______________to see inside Buckingham Palace. Peter : Yeah, maybe the Queen will be our tour guide ! Linda : I think we should join the queue. The last tour starts in ten minutes. David : What's the matter, Susan ? Are you OK ? Susan : NO, I don't feel very well. I have a headache and I feel really hot. Maybe I shouldn't come on the tour. David : Hey, everyone. Susan doesn't feel very well. (2)_________________but I think we should go home with her. Peter : But how about these tickets ? (3)__________________. We can't go home ! David : Yes, we can. (4)________________we can het our money back. Answer the questions. 1. What does David want to see ? ______________________________________________________________________________ 2. Are the friends in the quese yet ? ______________________________________________________________________________ 3. Who feels ill ? _______________________________________________________________________________ 4. What does David want them to do ? ________________________________________________________________________________ 5/. Were the tickets expensive ? Why can they go home ? __________________________________________________________________________________

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