直线与平面垂直性质 Evaluation only. Evaluation only. Created with Client Profile . Created with Client Profile . Copyright 2004-2011 Aspose Pty Ltd. Copyright 2004-2011 Aspose Pty Ltd. 一、复****与引入: 1、线面垂直的概念 2、如何判定线面垂直? 1、定义 2、判定定理 3、在空间,过一点,有几条直线与已知平面垂直?过一点,有几个平面与已知直线垂直? Evaluation only. Evaluation only. Created with Client Profile . Created with Client Profile . Copyright 2004-2011 Aspose Pty Ltd. Copyright 2004-2011 Aspose Pty Ltd. 如果两条平行线中的一条垂直于一个平面,那么另一条也垂直于这个平面. 4、我们已经知道: 那么: 如果两条直线同垂直于一个平面,那么这两条直线是否平行? Evaluation only. Evaluation only. Created with Client Profile . Created with Client Profile . Copyright 2004-2011 Aspose Pty Ltd. Copyright 2004-2011 Aspose Pty Ltd. abα二、新课讲授: 1、问题: // a b a b ? ?? ??,是否成立? O b’β Evaluation only. Evaluation only. Created with Client Profile . Created with Client Profile . Copyright 2004-2011 Aspose Pty Ltd. Copyright 2004-2011 Aspose Pty Ltd. 2、直线和平面垂直的性质定理: 符号语言: 图形语言: 如果两条直线同垂直于一个平面,那么这两条直线平行. β abα// a b a b ? ?? ??, Evaluation only. Evaluation only. Created with Client Profile . Created with Client Profile . Copyright 2004-2011 Aspose Pty Ltd. Copyright 2004-2011 Aspose Pty Ltd. Q 3、直线到平面垂直的距离: 从平面外一点引这个平面的垂线,这个点和垂足间的距离叫做这个点到这个平面的距离. P PQααQ点称为 P点在这个平面上的射影. Evaluation only. Evaluation only. Created with Client Profile . Created with Client Profile . Copyright 2004-2011 Aspose Pty Ltd. Copyright 2004-2011 Aspose Pty Ltd. 4、例题讲解: , 直线上各点到平面的距离相等. l? l ?互相平行的直线和平面的距离: 一条直线和一个平面平行时,这条直线上任意一点到这个平面的距离,叫做这条直线和这个平面的距离. Evaluation only. Evaluation only. Created with Client Profile 5
2.3.3直线和面垂直—性质 来自淘豆网www.taodocs.com转载请标明出处.