Ta có: `hat{xOy}` và `hat{yOz}` là hai góc kề bù
`=> hat{xOy} + hat{yOz} = 180^o`
Lại có:
+ `Ot` và `Ot'` lần lượt là tia phân giác của `hat{xOy}` và `hat{yOz}`
`=> hat{tOy} = 1/2hat{xOy} ; hat{t'Oy} = 1/2hat{zOy}`
mà `hat{ tOt'} = hat{tOy} + hat{t'Oy}`
`=> hat{ tOt'} = 1/2hat{xOy} + 1/2hat{zOy}`
`=> hat{ tOt'} = 1/2 . (hat{xOy} +hat{zOy})`
`=> hat{ tOt'} = 1/2 . 180^o `
`=> hat{ tOt'} = 90^o `
Vậy `hat{ tOt'} = 90^o `
(Chúc bạn học tốt)
Đáp án:
Giải thích các bước giải:
Vì `∠xOy` và `∠yOz` là hai góc kề bù.
`⇒ ∠xOy + ∠yOz = 180^0`
Do `Ot` là tia p/g của `∠xOy` và `∠yOz`
`⇒ ∠xOt = ∠yOt = 1/2 ∠xOy`
Do `Ot'` là tia p/g `∠yOz`
`⇒ ∠yOt' = ∠xOt' = 1/2 ∠yOz`
Ta có: `∠tOt' = ∠yOt + ∠yOt' = 1/2∠xOy + 1/2∠yOz = 1/2(∠xOy + ∠yOz)`
`⇒ 1/2 × 180^0 = 90^0`
1/ They will build a new school next year. (Change into the passive voice) ________________________________________________________________________ 2/ I don’t know many words in English. I wish __________________________________________________________________ 3/ Nga (do)_____________ that exercise for 3 days. (Put the verb in parentheses into the correct tense) 4/ People use the telephone to communicate in a long distance. (Change into the passive voice) _______________________________________________________________________
khai triển hằng đẳng thức sau (x+2)^2 đơn giản zị đó mn
giúp mình nha mọi người xin cảm ơn ><
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Đố bạn có bao nhiêu chữ C trong câu sau đây: “ Cơm, canh, cháo gì tớ cũng thích ăn!” .
Cali hộ em chữ : Chúc Bo thi tốt - Cali - Bằng app nhé ạ - Trang trí sách vở + vài đồ mùa hè - Thêm những gì tri thức tí - Chữ màu xanh nhạt nhé ạ NL : Nhanh giúp ek?
In the 1960s, many university and college students wore jeans. Designers made different styles of jeans to match the 1960s’ fashions: embroidered jeans, painted jeans, and so on. In the 1970s more and more people started wearing jeans because they became cheaper. In the 1980s jeans finally became high fashion clothing. The sale of jeans went up and up. But in the 1990s the worldwide economic situation got worse, the sale of jeans stopped growing. Questions: 1/ Who liked to wear jeans in the 1960s? _______________________________________________________________________ 2/ Why did more and more people begin wearing jeans in the 1970s? _______________________________________________________________________ 3/ What happened when jeans became high fashion clothing in the 1980s? _______________________________________________________________________ 4/ When did the sale of jeans stop growing? _______________________________________________________________________
cấu trúc tổng phân hợp là gì vậy, giải thích rõ ràng
I. Đọc văn bản và trả lời các câu hỏi sau. Đối với các câu hỏi 1, 2 viết câu trả lời vào chỗ trống sau mỗi câu hỏi (có thể trả lời ngắn gọn nhưng phải đủ ý); đối với các câu hỏi 3, 4, 5 khoanh tròn A, B, C hoặc D ứng với phương án đúng để hoàn chỉnh câu. (1.0p) Along with jogging and swimming, cycling is one of the best all-round forms of exercise. It can help to increase your strength and energy, giving you more efficient muscles and stronger heart. But increasing your strength is not the only advantage of cycling. Because you’re not carrying the weight of your body on your feet, it’s a good form of exercise for people with painful feet or backs. However, with all forms of exercise it’s important to start slowly and build up gently. Doing too much too quickly can damage muscles that aren’t used to working. If you have any doubts about taking up cycling for health reasons, talk to your doctor and ask his/her advice. Ideally you should be cycling at least two or three times a week. For the exercise to be doing you good, you should get a little out of breath. Don’t worry that if you begin to lose your breath, it could be dangerous and there must be something wrong with your heart. This is simply not true; shortness of breath shows that the exercise is having the right effect. However, if you find you are in pain then you should stop and take a rest. 1. According to the passage, how often should we go cycling? ______________________________________________________________________________. 2. Why is cycling a good form of exercise for people with painful feet or backs? ______________________________________________________________________________. 3. All forms of exercise must be started ________. A. quickly B. gradually C. strenuously D. violently 4. You should not worry about the shortness of breath because _________. A. it is a sign of exercise having the right effect B. it shows that you should stop and take a rest C. it shows that there is something wrong with your heart D. it is a sign of your getting rid of your heart problem 5. Which of the following is NOT included in the advantages of cycling? A. giving you a stronger heart B. increasing your strength and energy C. making you look younger D. giving you better mulses
1 Mary has running for hours and hours It's............................................................... 2 Tom is ill. He become ill three two days ago Tom has.......................................................... 3 It's 2 years since she left university She.............................................................. 4 This is the hottest year I have ever experienced I........................................................................... Mn giúp em vs ạ hứa cho ctlhn
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