Cho tam giác ABC nhọn và cân tại A, đường cao AH (H∈BC). a/ Hai tam giác ABH và ACH có bằng nhau không? Vì sao? b/ Tia AH có phải là tia phân giác của góc BAC không? Vì sao? c/ Kẻ tia phân giác BK (K ∈ AC) của góc ABC. Gọi O là giao điểm của AH và BK. Chứng minh rằng CO là tia phân giác của góc ACB.

giải bài 54 câu d,e,f hộ mình nha bài này là bài phân tích đa thức thành nhân tử bằng cách phối hợp nhiều phương pháp

Tính diện tích tấm bìa hcn có chiều rộng bằng $\frac{4}{7}$ chiều dài và chiều rộng kém chiều dài 30m

Hòa 10g kali hiđroxit vào nước thu được 200g dung dịch. Tính nồng độ phần trăm của dung dịch Mong mn giúp ạ

Viết một bài văn tả Tết bằng tiếng anh 1 trang hơn

Câu 3. Viết đoạn văn diễn dịch khoảng 12 câu, chứng minh nhận định: Trong văn bảnNước Đại Việt ta, tác giả Nguyễn Trãi đã khẳng định rõ chân lí về sự tồn tại độc lập,có chủ quyền của dân tộc Đại Việt.. Trong đoạn văn có sử dụng thán từ và câu phủđịnh. (chú thích rõ)

Các bạn ơi giúp mình với 🥺🥺🥺🥺

giúp mình với mình cần gấp hứa vote 5 sao

Tính bằng 2 cách. ( 1/3 + 2/5 ) x 3/4

71. John ________ his parents in France at the moment. He ________ in New York, but ________ his parents for the past few weeks. A. was visiting / live / had visited B. has visited / lived / is visiting C. is visiting / lives / has been visiting D. has been visiting / had live / has been visiting 72. -________ to come over for dinner tonight? - Oh, I’m sorry, I can’t. I _______ to a movie tonight with some friends. A. Have you wanted / will go B. Did you want / went C. Do you want / am going D. Are you wanting / go 73. He _______ a good day until a thief ________ into his apartment, _______ all his money, and _______ him up. A. has been having / comes / takes / tied B. had been having / came / took / tied C. was having / had came / took / tied D. is having / is coming / has take / ties 74. - Where ________ on holiday? - I don’t know. We ________ yet. A. will you go / are not going to decide B. are you going / have not decided C. have you gone / do not decide D. did you go / had not decided 75. When I ________ the street I ________ somebody call my name. A. have crossed / hear B. had crossed / would hear C. am crossing / will hear D. was crossing / heard 76. The train ________ at 8.58, so we ________ in Scotland by lunchtime. A. leaves / will be B. left / have been C. has left / were D. left / had been 77. I think by the time we ________ there, Jim ________ A. get / will have left B. got / has left C. will get / will leave D. had got / left 78. I ________ the time when I ________ as a teacher. A. have never forgot / have first worked B. am never forgetting / first work C. will never forget / first worked D. had never forgot / was first working 79. Women ________ in presidential elections since 1921. A. vote B. have voted C. had voted D. are voting 80. By the time the boss ________ at 9.00, his employees ________ for two hours. A. will arrive / are working B. arrives / will have been working C. arrived / have been working D. has arrived / were working 81. - I am hungry. I ________ lunch yet. - Don’t worry. I ________ you a sandwich. A. have not had / will get B. do not have / am going to get C. will not have / have got D. am not having / get 82. Do you think everything ________ when we ________ from the store? A. will be finished / get back B. is finished / will get back C. is going to finish / are getting back D. has been finished / will have got back 83. Look! Mary ________ a beautiful new dress. She ________ so pretty in the dress. A. was wearing / looked B. wears / has looked C. has been wearing / is looking D. is wearing / looks 84. I am sick of rain and bad weather! Hopefully, when we ________ up tomorrow morning, the sun ________. A. will wake / will shine B. are waking / shines C. are going to wake / is shining D. wake / will be shining 85. When the president ________ off the plane, the crowd ________ for him for half an hour. A. gets / will wait B. got / had been waiting C. had got / was waiting D. has got / will be waiting 86. Jane ________ at my house when you ________ A. is / will arrive B. will be / will arrive C. will be / arrive D. is / are going to arrive 87. They ________ here for three years before you ________ last week. A. have worked / came B. have been working / come C. was working / had come D. had been working / came 88. These students ________ hard since the beginning of the school year because they ________ their graduation exam next May. A. studied / are going to take B. are studying / will be taking C. study / will have taken D. have been studying / will take 89. The students ________ chapter 5 next week, so they ________ to prepare for It now. A. have studied / will read B. are studying / have read C. will study / read D. will be studying / are reading