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北师大初中数学九年级上册相似多边形2教案
(2)相似多边形的对应边的比称为相似比；(3)当相似比为1时，两个多边形全等．二、运用相似多边形的性质．活动3 例：如图27.1-6，四边形ABCD和EFGH相似，求角 的大小和EH的长度 ．27.1-6教师活动:教师出示例题，提出问题；学生活动:学生通过例题运用相似多边形的性质，正确解答出角 的大小和EH的长度 ．(2人板演)活动41．在比例尺为1﹕10 000 000的地图上，量得甲、乙两地的距离是30 cm，求两地的实际距离．2．如图所示的两个直角三角形相似吗？为什么？3．如图所示的两个五边形相似，求未知边 、 、 、 的长度．教师活动:在活动中,教师应重点关注：（1）学生参与活动的热情及语言归纳数学结论的能力；（2）学生对于相似多边形的性质的掌握情况．三、回顾与反思．(1)谈谈本节课你有哪些收获．(2)布置课外作业：教材P88页习题4.4
北师大初中九年级数学下册二次函数2教案
4．x的值是否可以任意取?如果不能任意取，请求出它的范围，[x的值不能任意取，其范围是0≤x≤2]5．若设该商品每天的利润为y元，求y与x的函数关系式。[y=(10－8－x) (100＋100x)(0≤x≤2)]将函数关系式y=x(20－2x)(0 ＜x ＜10＝化为：y=－2x2＋20x (0＜x＜10)…(1)将函数关系式y=(10－8－x)(100＋100x)(0≤x≤2)化为：y=－100x2＋100x＋20D (0≤x≤2)…(2)三、观察；概括1.教师引导学生观察函数关系式(1)和(2)，提出问题让学生思考回答；(1)函数关系式(1)和(2)的自变量各有几个? (各有1个)(2)多项式－2x2＋20和－100x2＋100x＋200分别是几次多项式?(分别是二次多项式)(3)函数关系式(1)和(2)有什么共同特点? (都是用自变量的二次多项式来表示的)(4)本章导图中的问题以及P1页的问题2有什么共同特点？让学生讨论、归结为：自变量x为何值时，函数y取得最大值。2．二次函数定义：形如y=ax2＋bx＋c (a、b、、c是常数，a≠0)的函数叫做x的二次函数， a叫做二次函数的系数，b叫做一次项的系数，c叫作常数项．
大班数学教案：分礼物
活动准备：幼儿每人一份操作材料，背景图、几何图形纸4张、剪刀浆糊、巧克力糕、糖、巧克力、笔、抹布。 活动过程：小朋友很喜欢自己的妈妈，妈妈也有自己的妈妈，妈妈的妈妈叫什么？爸爸也有自己的妈妈，爸爸的妈妈叫什么？爸爸妈妈都爱自己的孩子，辛辛苦苦把自己的孩子养大。熊妈妈有两张圆形纸，两张圆形纸一样大。她拿一张给两只小熊，要小熊把圆形纸分成一样大小的两份，一份给奶奶，一分给外婆。小朋友猜一猜，两只小熊用什么办法分这张纸？幼儿讲述
小班数学教案 超市购物
2、正确判断并找出一模一样的物品。 活动准备： 教具：橙边大卡片4张、红边大卡片16张（4组，每组4张）、小猴大卡片1张、磁铁（自备）。 幼儿材料：<超市购物>游戏图、<购物单>卡片。活动过程：一、引入活动 1、介绍新朋友。 师：“小朋友，你们看今天有一位客人来这里，它是谁？” 2、欢迎新朋友。 师：“哦！我们对它表示欢迎吧！”（师带领幼儿一起鼓掌） 3、为新朋友起名字。 师：（拿起小猴子大卡片遮住脸，声音稍变，模仿小猴子）说：“你们好，小朋友！你们认识我吗？知道我叫什么名字吗？帮我取一个吧？”（老师挑一个幼儿起的名字运用，如‘花花’等）
大班艺术节奏乐：“数高楼”课件教案
2，在“数高楼”这一音乐游戏中，培养幼儿打击4/4，2/4拍音乐的节奏，并在此基础上进行一2/4拍乐曲的节奏的不同打法。 3，培养幼儿的协商合作能力，及音乐表现力。准备：1、画有楼房的表格2张，空表格3—6张及若干可用于粘贴的楼房画； 2、录音机 数高楼的音乐磁带过程：（一）听《铃儿响叮当》音乐幼儿坐到位置上； 1、发声练习 提醒幼儿用轻声，并将身体坐正； 2、复习歌曲《数高楼》 指出其中不足之处。
2022年海南省中考英语真题（解析版）
In the late autumn, John was badly ill andbecame bedridden (长期卧床的).After the doctor visited John several times, he told Sue, “His condition isquite ___22___.John seems to have lost all will to live. If he doesn’t want to live, medicineswill not help him.”
2022年海南省中考英语真题（原卷版）
YangHongwei, 56, was born into a kite-making family in Weifang. When she was young,she often saw kites with bright colors and different shapes in hergrandfather’s workshop.
2022年河南省中考英语真题（原卷版）
In the large yard stood thirteen trees ofdifferent sizes. One day, while Joey was playing with his sister under thetrees, he noticed that a tree trunk (树干) had a sad look. He raninto the house to tell his mom about it. She told Joey to find the reason whyit was sad.
2022年河北省中考英语真题（原卷版）
As a boy, Kevin visited national parks and helearned the Earth is in ___12___ condition. He felt worried, and hewanted to ___13___ the Earth. In 2009, he went to swim in water nearNorth Pole（北极）todraw people’s attention to the melting glaciers（融化的冰川）.
2022年江西省中考英语真题（原卷版）
Long ago, a poor old couple lived on the coast.One day, an old storyteller came to their village. The old couple gave him ameal. In return, he gave them a coffee mill (磨粉机)and said, “Say, ‘Mill, please grind (磨粉)’,”
2022年河南省中考英语真题（解析版）
In the large yard stood thirteen trees ofdifferent sizes. One day, while Joey was playing with his sister under thetrees, he noticed that a tree trunk (树干) had a sad look. He raninto the house to tell his mom about it. She told Joey to find the reason whyit was sad.
2022年河北省中考英语真题（解析版）
As a boy, Kevin visited national parks and helearned the Earth is in ___12___condition. He felt worried, and he wanted to ___13___ the Earth. In 2009, he went to swim in waternear North Pole（北极）todraw people’s attention to the melting glaciers（融化的冰川）.
2022年江西省中考英语真题（解析版）
The app — called Sit With Us — is ___15___. If a student is having lunch in the afternoon,he or she can create an invitation. Other students can open the app and ___16___ that invitation. They can then use the app todecide when and where to ___17___.
2022年福建省中考英语真题（原卷版）
Thinking that her dream could never come true,Kelly was in low spirits and ____18____ her studies at school. Hermother did all she could to cheer her up, ____19____ Kelly refused tochange. She even took out all her anger and ____20____ on her mother.
2022年福建省中考英语真题（解析版）
At the age of nine, Kelly dreamed of being abasketball player. But one day when she was playing basketball, she hurt herleft leg ____16____.
2022年安徽省中考英语真题（解析版）
Antarctica lies in the most southern part of theworld. It is the coldest area on Earth. There isn’t much rain, but there is alot of snow and wind. The lowest temperature was on 21 July in 1983 at -89.2℃!
2022年安徽省中考英语真题（原卷版）
During 1907-1909, British explorer EarnestShackleton explored Antarctica on foot. In 1911, two explorers—a British mannamed Scott and a Norwegian named Amundsen—raced 1, 400 kilometres to the SouthPole (南极).Amundsen arrived first.
2022年吉林省中考英语真题（原卷版）
Taiping nijiaojiao is made of the mudfrom the local mountain. It takes more than ten steps to make the clay toy, andthe key step is to knead (捏) it with your hands. You can knead the clay toyinto anything, like animals and plants. The blowhole is the most difficult partto make, for the size of the blowhole makes a difference to the sound. Whilecoloring, you can use traditional cultural elements (元素) thatcarry good meanings. It’s hard to make taipingnijiaojiao. But when you finally make it, you will feel proud of yourself.
2022年吉林省中考英语真题（解析版）
“Red Trip” in TonghuaTonghua is a good choice to have a “red trip”. It is aplace full of “red stories”. The well-known national hero Yang Jingyu oncefought here. Experience the “red spirit”!
2022年北京市中考英语真题（解析版）
I joineda band （乐队）as a drummer in my middle school. I thought itwould be fun playing the drum and meeting new friends. At first it was easy,but a month later, it got difficult. I was the only one who couldn’t keep pace （节奏）with the other players. Our teacher,Angie, singled me out to keep practicing while everyone else got to relax. Ifelt ashamed （羞愧的）as my teammates watched me fail so many times.Finally I got so tired of practicing that I didn’t care about doing it right.
