Cho tam giác ABC cân tại A (Aˆ<90∘) . Vẽ BH vuông góc với AC (H thuộc AC), CK vuông góc với AB (K thuộc AB). a) Chứng minh rằng BH = CK. b) Gọi I là giao điểm của BH và CK. Chứng minh AI là phân giác của góc A. c) Lấy M là trung điểm của HK. Chứng minh rằng A, M, I thẳng hàng.

Cho $a_{1}$ > $a_{2}$ > $a_{3}$ > ..... $a_{9}$ > 0 . CMR : $\frac{a_{1} + a_{4} + a_{7} }{a_{1} + a_{2} + ..... + a_{9}}$ > $\frac{1}{3}$

Cho ba số dương thỏa mãn a+b+c=1 1/a^2 + 1/b^2 + 1/c^2 + 3≥2(a+b+c)

Giải phương trình: x² + 5x + 6 = 0

Việt một đoạn văn ngắn về tiếng Anh nói về giao thông ở Ninh Bình

Giúp mình câu này với Câu Chứng minh câu "Chớ nên tự phụ" Giúp mình với ạ mai phải nộp rồi

tìm các phân số bằng nhau trong các phân số sau 10/5 ; 14/18 ; 15/20 ; 16/40; 36/48; 63/81

CÂU ĐIỀU KIỆN 1,she doesn't live in London because she doesn't know anyone there she'd............................. 2,i can't live in the country because i can't find a job there i'd...................... 3,i don't have a spare ticket . i can't take you to the concert if i ............... 4,the school children sowed some needs, but they forgot to water them so they didn't grow if the children.................. 5,they don't understand the problem. they won't find a solution if they...........................

TAll Sf the following: A. cirque glaciers g TUm the view B. ic- gwings and sitting still among the leaves with similar colours ying among colourful flowers e following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 43 to 50. There are two basic types of glaciers, those that flow outward in all directions with little regard for a underlying terrain and those that are confined by terrain to a particular path. The first category of glaciers includes those massive blankets that cover whole continents, appropriately called ice sheets. There must be over 50,000 square kilometers of land covered with ice the glacier to qualify as an ice sheet, when portions of an ice sheet spread out over the ocean, they fon shelves. About 20,000 years ago the Cordilleran Ice Sheet covered nearly all the mountains in southern Alaska, western Canada, and the western United States. It was about 3 kilometers deep at its thickest p in northern Alberta. Now there are only two sheets left on Earth, those covering Greenland and Antarc Any domelike body of ice that also flows out in all directions but covers less than 50,000 squar kilometers is called an ice cap. Although ice caps are rare nowadays, there are a number in northeastern Canada, on Baffin Island, and on the Queen Elizabeth Islands. The second category of glaciers includes those of a variety of shapes and sizes generally called mountain or alpine glaciers. Mountain glaciers are typically identified by the landform that controls thei flow. One form of mountain glacier that resembles an ice cap in that it flows outward in several directio is called an ice field. The difference between an ice field and an ice cap is subtle. Essentially, the flow an ice field is somewhat controlled by surrounding terrain and thus does not have the domelike shape o! cap. There are several ice fields in the Wrangell. St. Elias, and Chugach mountains of Alaska and northe British Columbia. Less spectacular than large ice fields are the most common types of mountain glaciers: the cirque and valley glaciers. Cirque glaciers are found in depressions in the surface of the land and have a characteristic circular shape. The ice of valley glaciers, bound by terrain, flows down valleys, curves around their corners, and falls over cliffs. Question 43. What does the passage mainly discuss? A. Where major glaciers are located C. The different kinds of glaciers B. How glaciers shape the land D. How glaciers are formed Question 44. The word "terrain" in paragraph 1 could best be replaced by B. area of land C. countryside D. prairie A. the seabed

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