1、(完整word版)第一章_丰富的图形世界复习教案丰富的图形世界知识体系:(1)常见的几何体;(2)构成图形的基本元素点、线、面及点、线与平面图形的一些简单性质; 点动成线,线动成面,面动成体(3)棱柱的特征;并注意棱柱和圆柱的联系与区别(4)长方体、正方体的表面沿某些棱展开的平面图形及圆柱、圆锥的侧面展开图;(5)用一个平面去截一个几何体,截面的形状;(6)物体的三视图,立方体及其简单组合的三视图;(7)生活中的平面图形重点与难点:点、线、面等最基本的图形于基本几何体的相互转换. 在面与体的变化中如何抓住特征题型体系:1.几何体的展开图:几何体的表面展开图通常包括几何体的底面与侧面,因此应先确
2、定底面,再确定侧面,可以采用“做一做,折一折”的方法,形成里自己的空间观念。例1(1)如图所示,图中五角星状的图形沿虚线折叠,得到一个几何体,你在生活中见过和这个几何体类似的物体吗?分析:通过该几何体的表面展开图可以判断出其底面是五边形、而侧面是三角形,由此判读其应属于锥体。(2) (10,中原区,期中)以下四个平面图形中,不是正方体的展开图的是( ) A B C D(3)(11,焦作,期末)右图是某一立方体的侧面展开图 ,则该立方体是 () (4)只有盖的盒子长、宽、高分别为5、5、3cm,如图所示,有一只蚂蚁从A点出发,沿棱爬行,爬行的路径不许重复,则蚂蚁回到A点时,最多爬行( )A24c
3、m B32cm C34cm D48cm2.平面图形的折叠例2.(1)你能设计一个三棱锥、四棱锥吗?分析:由锥体的特征展开思考。(2)(10,中原区,期中)下列各图经过折叠后不能围成一个正方体的是( )A B C D3.几何体的截面图例3.用平面去截一个正方体、圆柱体、六棱柱,则截面分别为 分析:先找平面与几何体相交的线,再判断这些线围成的图像 4.几何体的三视图:本章的重点研究由小立方体搭成的几何体的三视图。画这类几何体的三视图关键是确定他们有几列,以及每列中方块的个数。例4. (11,焦作,期末)若右图是某几何体的三视图,则这个几何体是主视图左视图例5(10,中原区,期中)一个几何体是由若干
4、个相同的正方体组成的,其主视图和左视图如图所示,则这个几何体最多可由多少个这样的正方体组成12个 13个14个 18个变式(11,焦作,期末)下图是一些完全相同的小立方块搭成的几何体的三种视图,那么搭成这个几何体所用的小立方块的个数是 . 例6(11,新密,期中)(1)如图所示是由几个小立方块所搭的几何体的俯视图,小正方形中的数字表示在该位置小立方块的个数,请画出相应几何体的主视图和左视图:(每个图2分,计4分)主视图: 左视图: (2)分别画下图几何体的主视图、左视图、俯视图。(每个图2分,计6分)主视图:左视图:俯视图:变式(11,焦作,期末)(9分)下图是由一些相同的小立方块搭成的几何体
5、,请画出这个几何体的三视图. 主视图 左视图 俯视图4.思想方法专题:从特殊到一般的思想,即从特例入手,探究规律,再推广到一般情况这是数学中发现问题,解决问题的一般做法。例7.观察如图所示的图案,他们都是由边长为1cm的小正方形按一定规律拼接而成的,依次规律,则地16个图案中的小正方形有( )个。 分析:第n个图案中,正方形的个数用an表示,则a1=1, a2=1+2,a3=1+2+3,a4=1+2+3+4, a16 = 1+2+3+4+16=136练习题一、选择题(每小题3分,共36分)1. 用一个平面去截一个正方体,截面不可能是( )A三角形 B梯形 C圆 D五边形2. 下面图形不是正方体
6、展开图的是( )3. 下图中截面是正方形的是( )4. 长方体的顶点数、棱数、面数分别为( )A8,10,6 B6,12,8 C6,8,10 D8,12,65. 如图,下列图形经过折叠,可以围成一个棱柱的是( )6. 如图,虚线左边的图形绕虚线旋转一周,能形成的几何体是( )7经过五棱柱的一个顶点的棱有( ) A3条 B4条 C5条 D6条8把一个正方体截去一个角,剩下的几何体最多有几个面( )A5个面 B6个面 C7个面 D8个面9从多边形一条边上的一点(不是顶点)发出发,连接各个顶点得到2005个三角形,则这个多边形的边数为( ).A2005 B2006 C2007 D200810. 下列
7、四个图形折叠后与所得的正方体的各个面上所标数字一致的是( )11. 如图(1)是正方体表面积展开图,如果将其折回原来的正方体图(2)时,与点P重合的两点应该是( )AS和Z BT和Y CU和Y DT和V12将一正方形纸片按图中(1)、(2)的方式依次对折后,再沿(3)中的虚线裁剪,最后将(4)中的纸片打开铺平,所得图案应该是下面图案中的( )二、填空题(每小题4分,共24分)1薄薄的硬币在桌面上转动时,看上去象球,这说明了_.2.在长方体、球、圆锥、圆柱、三棱柱这五种几何体中,其主视图、左视图、俯视图都完全相同的是 (填上序号即可) 3.一个棱柱有十个顶点,且所有侧棱的和为30cm,则每条侧棱
8、长为 cm. 4. 如图是一些相同的正方块构成的立体图形的三视图,则构成这个立体图形的小方块数为 . 5如图所示,木工师傅把一个长为1.6米的长方体木料锯成3段后,表面积比原来增加了80,那么这根木料本来的体积是 6如图 ,电视台的摄像机1、2、3、4在不同位置拍摄了四幅画面,则A图象是_号摄像机所拍,B图象是_号摄像机所拍,C图象是_号摄像机所拍,D图象是_号摄像机所拍. 三、解答题(每小题8分,共40分)1如图所示,是由几个小立方体木块搭成的几何体的俯视图,小正方形中的数字表示该位置小立方块的个数,根据这个条件,你能画出这个几何体的主视图和左视图吗?试试看! 2某宾馆在重新装修后,考虑在大
9、厅内的主楼梯上铺设地毯已知主楼梯宽3m,其剖面如图所示,请你计算一下,仅此楼梯,需要购买地毯多少平方米?3. 把一个长方形绕它的一条边所在的直线旋转一周能得到一个圆柱体,那么把一个长为8cm,宽为6cm的长方形,绕它的一条边所在的直线旋转一周后,你能计算出所的圆柱体的体积吗?(结果保留)4. 在草原上有一个边长为3米的正方形小房子,一只羊拴在墙角,绳子的长是4米,你能计算出羊吃到草的面积约是多少吗?(取3.14)5(1)画出图1几何体的三种视图;(2)用小立方块搭成的几何体,主视图和俯视图如图2,问这样的几何体有多少可能?它最多需要多少小立方块,最少需要多少小立方块,请画出最少和最多时的左视图
10、. 图1 图2技术官员村位于位于亚运城东部,主干道二以东石楼涌以西的地块,占地面积、m2,总建筑面积、m2,共包括地下室南区、地下室北区、地上部分1栋12栋、服务中心、室外工程等多个单体工程。其中住宅面积m2,共12栋,17栋建筑层数为11层,812栋11层(局部复式顶层),首层局部架空,布置公建配套设施。integrated energy, chemicals and textile Yibin city, are the three core pillars of the industry. In 2014, the wuliangye brand value to 73.58 billi
11、on yuan, the citys liquor industry slip to stabilise. Promoting deep development of integrated energy, advanced equipment manufacturing industry, changning district, shale gas production capacity reached 277 million cubic metres, built the countrys first independent high-yield wells and pipelines in
12、 the first section, the lead in factory production and supply to the population. 2.1-3 GDP growth figure 2.1-4 Yibin, Yibin city, Yibin city, fiscal revenue growth 2.1.4 topography terrain overall is Southwest, North-Eastern State. Low mountains and hills in the city landscape as the main ridge-and-
13、Valley, pingba small fragmented nature picture for water and the second land of the seven hills. 236 meters to 2000 meters above sea level in the city, low mountain, 46.6% hills 45.3%, pingba only 8.1%. 2.1.5 development of Yibin landscapes and distinctive feature in the center of the city, with lim
14、itations, and spatial structure of typical zonal group, 2012-cities in building with an area of about 76.2km2. From city-building situation, old town-the South Bank Center construction is lagging behind, disintegration of the old city is slow, optimization and upgrading, quality public service resou
15、rces are still heavily concentrated in the old town together. Southbank Centre has not been formed, functions of the service area space is missing. Meanwhile, peripheral group centres service was weak and inadequate accounting for city development, suspicious pattern could not be formed. As regards
16、transport, with the outward expansion of cities, cities have been expanding, centripetal city traffic organization has not changed, integrated energy, chemicals and textile Yibin city, are the three core pillars of the industry. In 2014, the wuliangye brand value to 73.58 billion yuan, the citys liq
17、uor industry slip to stabilise. Promoting deep development of integrated energy, advanced equipment manufacturing industry, changning district, shale gas production capacity reached 277 million cubic metres, built the countrys first independent high-yield wells and pipelines in the first section, th
18、e lead in factory production and supply to the population. 2.1-3 GDP growth figure 2.1-4 Yibin, Yibin city, Yibin city, fiscal revenue growth 2.1.4 topography terrain overall is Southwest, North-Eastern State. Low mountains and hills in the city landscape as the main ridge-and-Valley, pingba small f
19、ragmented nature picture for water and the second land of the seven hills. 236 meters to 2000 meters above sea level in the city, low mountain, 46.6% hills 45.3%, pingba only 8.1%. 2.1.5 development of Yibin landscapes and distinctive feature in the center of the city, with limitations, and spatial
20、structure of typical zonal group, 2012-cities in building with an area of about 76.2km2. From city-building situation, old town-the South Bank Center construction is lagging behind, disintegration of the old city is slow, optimization and upgrading, quality public service resources are still heavily
21、 concentrated in the old town together. Southbank Centre has not been formed, functions of the service area space is missing. Meanwhile, peripheral group centres service was weak and inadequate accounting for city development, suspicious pattern could not be formed. As regards transport, with the outward expansion of cities, cities have been expanding, centripetal city traffic organization has not changed,