Giúp mk với ạ Cho ΔABC, góc A =90 độ ,đcao AH.Vẽ HM ⊥AB,HN ⊥AC biết AB=3cm ,AC=4cm a)Tính MN b) Tính số đo các góc AMN c)Tính S BMNC

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Condional Type 1: 1. - Michael …………..… (help) his mom if she ………….. (ask) him. 2. - Lucy ………..…… (not come) on time if she ……………….. (miss) the bus. 3. - If the children ………………. (be) hungry, I …………….. (cook) something for them. 4. - Thomas ………….(buy) him another mobile if his parents ………….. (give) him the money. 5. - Alice and Sonia ………………. (not wear) sandals if the weather ………… (be) cold. 6. - If you ………….. (drink) very cold water, you …………. (get) sore throat. 7. - My mother ……………… (punish) me if I ……..….(break) something at home. 8. - Tea ………………. (be) ready if you ………………. (wait) three minutes. 9. - If George ……………… (drive) his car to work, he ………….. (waste) a lot of time. 10. -The taxi driver ……………… (stop) his car if the traffic lights ………… (be) red. 11. -Margaret ………………. (not have) lunch at home if she …………….. (have to) work until late. 12. -John ………………. (run) the marathon if he ………….. (feel) fit enough. 13. -Hector ………………… (not meet) his teacher if he ………….. (go) to the beach. 14. -Bernardo ……………… (play) basketball if his team …………….. (not be) too busy. 15. -If Natalie ………………… (sing) in the band, she …………….. (get) some money. Condional Type 2: 1.If I had a typewriter I (type) .................................. it myself. 2.If I (know) .................................. his address, I'd give it to you. 3.He (look) ..................................a lot better if he shaved more often. 4.If you (play) ..................................for lower stakes you wouldn't lose so much. 5.If he worked more slowly he (not make) .................................. so many mistakes. 6.I wouldn't drink that wine if I (be) ..................................you. 7.More tourists would come to this country if it (have) .................................. a better climate. 8.If I were sent to prison you (visit) ..................................me? 9.If someone (give) .................................. you a helicopter what would you do with it? 10.I (buy) ..................................shares in that company if I had some money. 11.If he (clean) .................................. his windscreen he'd be able to see where he was going. 12.If you drove your car into the river you (be able) ..................................to get out? 13.If you (not belong) ..................................to a union you couldn't get a job. 14.If I (win) ..................................a big prize in a lottery I'd give up my job. 15.What you (do) ..................................if you found a burglar in your house? Condional Type 3: 1.If Mary had been free yesterday I  .................................. (INVITE) her. 2.If the weather  .................................. (BE) miserable what would you have done ? 3.If you hadn't called I  .................................. (NOT KNOW) about the meeting. 4.If she had received an invitation she  .................................. (JOIN) us. 5.If it  .................................. (NOT RAIN) yesterday we would have gone on a picnic. 6.You would have done it if you  .................................. (TRY). 7.He  .................................. (NOT BE) so surprised if he had gone to their last meeting. 8.If I had bought some fresh food I  .................................. (NOT HAVE) to eat canned food for breakfast, 9.The constructors  .................................. (BUILD) the road if they had had enough tools. 10.The author would have finished the book he he  .................................. (NOT FALL) seriously ill. 11.The car engine  .................................. (WORK) if the mechanic had done his job properly. 12.He would have taken the job if he  .................................. (FIND) the offer acceptable. 13.If you  .................................. (to check) the car, it  .................................. (not/to break) down in the middle of the desert. 14.If it  .................................. (not/to rain), the children  .................................. (to play) outside. 15.If my parents  .................................. (not/to be) so tired, they  .................................. (to watch) the film on TV.