Cho hình bình hành abcd có hai đường chéo AC và BD cắt nhau tại o và AC = 2 x AB vẽ BK là trung trực của tam giác abo chứng minh góc ABK bằng góc ACB gọi m là trung điểm của BC chứng minh MK vuông góc với BD

Các câu hỏi liên quan

5. Flower oils are ________ of the ingredients used in making perfume. A. among expensive B. among the most expensive C. being most expensive D. very expensive 6. I met a lot of new people at the conference ________ names I can’t remember. A. whose B. which C. who D. whom 7. The little boy failed to give ________ reason for his absence from school last Monday. A. satisfactory B. correct C. adequate D. right 8. I will lend you the book providing that you ________ it not later than Sunday. A. will return B. return C. is returning D. returned 9. It is ________ to fail a job interview, but try again. A. disappoint B. disappointing C. disappointedly D. disappointment 10.New York Harbour, ________, is one of the largest and finest harbours in the world. A. where is ice-free in all seasons B. that is ice-free in all seasons C. which is ice-free in all seasons D. it is ice-free in all seasons there 11.The last family ________ was on the occasion of Grandma’s birthday two years ago. A. anniversary B. collection C. meeting D. gathering 12.Last month two terrible storms ________ the central provinces of Viet Nam. A. struck B. collapsed C. erupted D. buried 13.Cold temperatures, short growing seasons, and heavy snows prevent ________ at high elevations. A. grow trees B. trees are growing C. trees growing D. trees growth 14.________ is helping to break new ground in drug research. A. Computers are being used more B. When using computers more C. An increase in the use of the computers D. The increasing use of the computer Mark the letter A, B, C or D to indicate the word(s) CLOSEST in meaning to the