Ta có: Tam giác `ABC` và tam giác `ACD` có chung chiều cao
mà `CD = 1/3 BC`
`=>` Diên tích tam giác `ACD = 1/3` tam giác `ABC`
`=> 15cm^2 = 1/3` tam giác ABC
S tam giác `ABC` là:
`15 : 1 × 3 = 45 (cm^2)`
Đáp số: `45 cm^2`
(Chúc bạn học tốt)
Chiều cao của tam giác ACD và ABC đều bằng nhau là : AH
Vì đáy tam giác ACD = `1/3` ABC
⇒ S tam giác ACD = `1/3` S tam giác ABC
⇒ Tam giác ABC là :
15 : `1/3` = 45 (`cm^2`)
Đáp số : 45 `cm^2`
CHUYỂN TỪ CÂU GIÁN TIẾP SANG CÂU TRỰC TIẾP 1. She said she was too tired and didn’t want to go out. 2. She told me she wanted to be a designer 3. Her parents said design graduates wouldn’t find jobs easily and they wanted her to get a medical degree.
Làm hộ mình bài 4 phần a, b nhé
1. All bottles _____ before transportation. A. frozen B. will been frozen C. is frozen D. were frozen E. was frozen 3. Everything _____. A. are forbidden B. were forbidden C. is forbidden D. is forbidded E. will is forbidden 4. Everything _____.A. are going to be forgotten B. is going to be forgotten C. is going be forgotten 5. I _____.A. have not be given the money B. have not been give the money C. have not been given the money 6. It _____ for years. A. have not been known B. had not be known C. have not be known D. has not been known 7. John and Ann _____. A. was not misled B. was not misleed C. were not misled D. were not misleed E. were not misleeded 9. Our horses _____. A.are well fed B. are well feeded C. is well fed D. is well feeded E. well fed 10. Peter and Tom _____ in an accident yesterday. A. is hurt B. is hurted C. were hurt D. were hurted E. will been hurt 11. South Florida and Hawaii _____ by a hurricane. A. has been hit B. have been hit C. has be hit D. have are hit is hit 12. The battles for liberation _____. A. had be fought B. had been fighted C. had been fought D. has been fought 13. The best way _____. A. will had been found B.will found C. will be finded D. will be found E. will been found 14. The money _____ to me. A. have not been given B. has not be given C. has not been given D. has not been gaven 15. The mosquito bite _____. A. could not be feeled B. could not felt C. could not be felt D. could not be feel E. could not be fell 16. The picture _____ to a famous museum. A. is being lent B. are being lent C. is being lended D. are being lended 17. The stolen car _____ in the ditch. A. will been left B. had be left C. were leaved D. were left E. was left 18. The thing _____ secret. A. could not be keep B. could not be kept C. could not
các bạn làm cho mk cái bài toán này
1/Chứng minh $16^{5}$ + $2^{15}$ \vdots 33 2/So sánh $\frac{161}{160}$ và $\frac{9999}{9998}$
nhô mn nha này mn ơi vừa nãy mn có thấy dòng tb nhóm yokai jose ko ạ vừa nãy mk bảo cj cj ko tin nên lên đây hỏi để cj tin vẽ đậu mầm nha mn nl:cho mk chào mn nha
Làm cho mk với nhá cảm ơn trước
Mn giải giúp em ạ, cần giải thích.
help help help help help help help help help help help help
Cho tam giác ABC có cạnh BC = 20 cm. Kéo dài đáy BC thêm 6 cm thì diện tích tăng thêm 24 cm2. Tính diện tích tam giác ABC ?
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