长方体直观图的画法复习过程.ppt

,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,82长方体直观图的画法,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,复习,一、口答：,1,.,长方体有个面,个顶点,条棱；,2.长方体的每个面都是形；,3.长方体的棱可以分为组,每组中的条棱的长度相等；,4.长方体的面可以分为组,每组中个面的形状和大小都相同。,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,二、判断下列哪一个图形是左边正方体的侧面展开图？,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,平面,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,平面的表示,观察,一个正方形纸片平放在桌面上，你看到它还是正方形的形状吗？,A,B,D,C,在一个角上写上小写希腊字母表示：,用平行四边形的四个顶点字母表示：,水平的哟!,45,0,平面,平面,ABCD,表示,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,帮帮它,小熊要建造一座长方体的房子,可它搞不清的是盖房子的顺序:,是先砌墙呢?还是先打好地基?或者先盖房顶呢?,先,再,最后,打地基,砌墙,盖房顶,你认为:,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,讨论,观察,水平放置在桌面的长方体盒子,你最多能看到它的几个面?,三个面,如何将如图放置的长方体画下来呢?,交流结果:,一打地基(画底面);,二砌墙(画柱子);,三盖房顶(连线).,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,操作二,砌墙(画柱子),柱子即长方体的高,高要与底面垂直,结论,打地基(画底面),操作一,部分学生作品:,长方体的底面不能画为长方形,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,斜二侧画法,基本步骤(,学生与老师一起画,)：,1、画平行四边行,ABCD,，使,AB,等于长方体的长，,AD,等于长方体宽的二分之一,DAB,45,0,2、过A.B分别画AB的垂线AE、BF,过C、D分别画CD的垂线CG、DH,使它们的长度都等于长方体的高.,3、顺次连接EFGH.,4、将被遮住的线段改用虚线表示,A,E,D,C,B,F,G,H,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,试一试,请你画一个长、宽、高分别是5cm、4cm、3cm的长方体,A,E,D,C,B,F,G,H,长方体的表示方法,长方体ABCD-EFGH,或,长方体AG、,长方体BH等,六个面可表示为：,平面BCGF、平面EFGH等,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,课堂练习,1、用字母表示下列平面：,A,H,G,F,E,D,C,B,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,2、判断下列图形哪些是长方体，请用字母将其表示出来；,(3),Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,3、补画下面的图形，使之成为长方体的直观图,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,课堂小结,这节课你学到了什么？,斜二侧画法的要点是,作业布置,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,