user-avatar
lena0609
2 năm trước
Cho đường tròn (O;R) có đường kinh AB. Trên tia đối của tia AB lấy điểm E sao cho AE=R/2. Từ E vẽ tiếp tuyến EM của đường tròn (O) với M là tiếp điểm; tiếp tuyến tại A và tại B của (O) cắt đường thẳng EM tại C và D a) Chứng minh: Tam giác AMB vuông và AC+BD=CD b) OC cắt AM tại H và OD cắt MB tại K. Chứng minh: tứ giác MHOK là hình chữ nhật c) Chứng minh: MA.OD=MB.OC d) Tính diện tích hình thang ABDC theo R
Thích Trả lời Chia sẻ

Các câu hỏi liên quan

V. Fill in each blank with the simple past tense of the verb from the box " play, go, do, buy, teach, lose, score, win, become, enjoy" 1.My friends and I................ swimming yesterday morning 2.We really....................... the game last sunday 3.In 1958, at the age of 17, pelé...............................his first World Cup 4.The Canadian hockey team...............six goals against Switzerland 5.The home team..............very well, but they lost the match 6.My farther.................. me how to ride a bike 7.I...........a new baseball cap last week 8.At the age of 17,Messi...............the youngest official player and goal scorer in the Spanish La Liga 9.She has a black belt in karate. She first................karate when she was seven 10.Argentina.................1- 0 to Germany in the final. VI.Turn the sentences into negative and interrogative forms 1. They were in Rio last summer ...................................................... ........................................................ 2.We did our exercise this morning ..................................................... ..................................................... 3.My parents came to visit me last July .............................................................. ............................................................... 4.The hotel was very expensive ........................................................ ........................................................ 5.I had a bicycle when I was young ........................................................ ........................................................ 6. The children went to the zoo yesterday ........................................................ ......................................................... 7.Ernie ate the last doughnut ..................................................... ..................................................... 8.They bought a new house last month ...................................................... ..................................................... X.Complete these sentences using an imperative form ( positive or negative ) of the verbs in the box " Dress, get, not call, be, not exercise, not inturrupt, save, not worry" 1.............me between two and five this afternoon. I'll be in a meeting 2.Always..............your documents as soon as you finish writing them 3.............after you eat a big meal.It's not a goos idea 4..............me when I am speaking 5..............warmly so you don't get cold outside.It's snowing 6.............careful! you almost spilled your coffee 7................- we've got lots of time.The meeting doesn't start until 10.30 8 We need something to wake us up!........................a coffee

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