人教新课标数学五年级上册第五单元(平行四边形的面积）PPT课件

平行四边形的面积人教新课标五年级数学上册Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd.Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd. Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd.Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd. Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd.Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd. 高底宽长平行四边形底高面积长方形长宽面积6米4米24平方米6米4米24平方米(一个方格代表1m2，不满一格的都按半格计算)Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd.Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd. 1.利用你手中的学具,剪一剪、拼一拼，试把平行四边形转化为长方形。2.观察拼出的长方形和原来的平行四边形，你发现了什么？3.由长方形的面积=长×宽,你发现平行四边形面积的计算方法是什么?自探提示Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd.Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd. 高底宽长平行四边形面积的计算结论:平行四边形转化成了长方形所以:平行四边形的面积=底×高因为:长方形的面积=长×宽平行四边形可以转化成一个长方形，长方形的面积与原来平行四边形的面积＿＿＿。长方形的长与原来平行四边形的底＿＿＿。长方形的宽与原来平行四边形的高＿＿＿。相等相等相等Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd.Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd. S=ahahsEvaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd.Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd. 沿平行四边形的任意一条高剪开、平移，都可以得到长方形。Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd.Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd. Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd.Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd. 例1平行四边形花坛的底是6米，高是4米，它的面积是多少？4米6米S=ah=6×4＝24（平方米）答：它的面积是24平方米。Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd.Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd. 1、填空：①任意一个平行四边形都可以转化成一个长方形，它的面积与原来平行四边形的面积()。这个长方形的长与原来平行四边形的()相等，这个长方形的宽与原来平行四边形的()相等。因为长方形的面积=()，所以平行四边形的面积=()。②一个平行四边形的底是9厘米，高是3分米，它的面积是（　）平方厘米。知识乐园相等底高长×宽底×高270Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd.Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd. 2火眼金睛辨对错。①两个平行四边形的高相等，它们的面积就一定相等。()②平行四边形的底是20米,高是16米,它的面积是320米。（）③一块平行四边形菜地的面积是28平方米，底长7米，它的高是4米。（）×√×Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd.Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd. 2米3米2.7米①图中平行四边形的面积是（　）A　2×2.7＝5.4(平方米)B　3×2.7＝8.1(平方米)C　3×2＝6（平方米）②图中两个平行四边形的面积（　）A不相等B相等C无法判断将正确答案的序号填在括号里。3CBEvaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd.Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd. 本课小结本节课我们主要学习了哪些内容？同桌之间互相讨论一下！Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd.Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd.