两个无限大的平行平面

两题相似三角形题目!（1） 如图,△ABC中,∠BAC=90°,D为BC中点,过D作BC的垂线,交AB于E,交CA延长线于点F,求证:AD平方=DE×DF （2）已知,在Rt△ABC中,∠C=90°,D是BC上的一点,过点B作BE⊥AB,且∠BAE=∠DAC, Reported speech 题目--------高手请进1.Pansy said to us,“Would you like to come and stay for the weekend?”2.“I’ll help you type up that report,” Steve said.3.The doctor said,“You should take it easy for a few days,Tammy.”4.Peggy sa 能帮我改成reported speech吗?'where did you leave you bag,Mrs Wong?' asked the policeman.'which radio channel is Tim listening to?' asked Judy.'when does the stationery shop close?' asked Bob. reported speech 文法reported speech 什麼时侯需要加that,什麼时侯不需加that?例如,He said that he liked singing.He said she was going shopping 求一题相似三角形的题目,万急,已知在Rt△ABC中,∠BAC=90°,AB=AC,D为BC的中点,E为AC上一点,点G在BE上,连接DG并并延长交AE于F,若∠FGE=45°.试说明：AG⊥BE reported speech 中各种时态的变化past continuous becomes WHAT?Simple past becomes WHAT?…… 第四字带势字的成语 天上几只鹅. What are a main function of computer? 地震时怎样自卫 成语千里之行 His son is badly ill.He is()about him括号里怎样填 李敏镐后面的字读什么 噫,微斯人,吾谁与归这句话有什么深刻的含义 微斯人 急求大神帮我设计一个电子信息系系徽好么 英语首字母,i---b---r---L--p---f---l-- ,Like most teachers,Mrs.Thompson tells her students that she loves them all the same.But that is i.Just there in the front row sits a little boy named Teddy.Mrs.Thompson doesn't like Teddy b his clothes are 用a e i u f g p r r t 几个字母能组成多少个单词用a e i u f g p r r t 几个字母 不重复 组3-9个字母的单词 最好分开 3-4 5-6 7-8 9个以上的单词 答的好的话有加赏啊 mason怎么读?用中文写出来吧, 当得到别人赞美时应该怎么回应 别人赞美时如何回应 魁梧什么意思?谢谢 魁梧黧黑的意思?黧的意思? 帮个忙第一个点赞 帮个忙,给赞 物候现象的来临决定于哪些因素呢 中国历史上的三次经济南移及其意义 济南走读生是什么意思 甲乙两地相距520千米,两辆汽车从甲乙两地同时开出,从甲地开出的汽车A的速度是乙地开出的汽车B的速度的1又二分之一倍（1）如果这两辆汽车相背而行2小时,两车相距800千米,那么这两辆汽车 已知函数f(x)对一切实数x都满足f(1+x)=f(1-x),并且f(x)=0有三个实根,三个实数根之和是几 你一定会听见我的赞美 作文 我国文化被别人赞扬时我们的反应