必须修读2—第1章节2-1直观图.ppt

2.探求空间几何体的直观图的画法正棱锥的直观图的画法 直棱柱的直观图的画法 练习2.用斜二测画法画长,宽,高分别是4cm,3cm,2cm的长方体的直观图 * 1.1.4直观图画法 怎样学好本节课 ? Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 大家猜猜这些美丽的图画是什么? Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 水立方 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 鸟巢 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 澳大利亚悉尼歌剧院 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 卢浮宫 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 泰姬陵 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 金字塔 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 中华世纪坛 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 先讨论水平放置的平面图形的画法。 建构数学 A 0 B C Y X E D F M N A1 D1 N1 M1 B1 C1 F1 E1 01 y1 x1 例1、画水平放置的正六边形的直观图 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 总结画法规则： 2、已知图形中平行于x轴、y轴的线段，在直观图中分别画成平行于x’轴、y’轴的线段（即平行性不变）； 3、已知图形中平行于x轴的线段，在直观图中保持长度不变；平行于y轴的线段，长度为原来的一半(即横不变纵拆半）。 1、在已知图形中建立直角坐标系xoy.画直观图时，它们分别对应x’轴与y’轴，两轴交于o’,使∠ x’o’y’=45°；他们确定的平面表示水平平面。 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 例2、画水平放置的圆的直观图。 X O Y 0 X’ Y’ 数学运用 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 2探求空间几何体的直观图的画法 例2 画正六棱锥的直观图 六棱锥 返回 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copy