八年级数学下册-18.2.1矩形同步练习1-(新版)新人教版

leadership intention and meaning into the text. Although his eyes now write only a relatively small number of materials, but also quite difficult, even to a molding material herself seems not very satisfied with the quality of service needs to be enhanced.Three is a lot of work to implement passive, active and advanced. Most contractors do matters assigned by the leadership, work is often in the orders, to implement the task, do not want to lead, not want to think ahead, plan ahead, and to seek the leadership; seek deep into the research, provide information good staff seek. Especially in the writing process of material, it encountered much, time tight, heavy矩形学习要求理解矩形的概念，掌握矩形的性质定理与判定定理课堂学习检测一、填空题1(1)矩形的定义：_的平行四边形叫做矩形(2)矩形的性质：矩形是一个特殊的平行四边形，它除了具有四边形和平行四边形所有的性质，还有：矩形的四个角_；矩形的对角线_；矩形是轴对称图形，它的对称轴是_(3)矩形的判定：一个角是直角的_是矩形；对角线_的平行四边形是矩形；有_个角是直角的四边形是矩形2矩形ABCD中，对角线AC、BD相交于O，AOB60，AC10cm，则AB_cm，BC_cm3在ABC中，C90，AC5，BC3，则AB边上的中线CD_4如图，四边形ABCD是一张矩形纸片，AD2AB，若沿过点D的折痕DE将A角翻折，使点A落在BC上的A1处，则EA1B_。5如图，矩形ABCD中，AB2，BC3，对角线AC的垂直平分线分别交AD，BC于点E、F，连结CE，则CE的长_二、选择题6下列命题中不正确的是( )(A)直角三角形斜边中线等于斜边的一半(B)矩形的对角线相等(C)矩形的对角线互相垂直(D)矩形是轴对称图形7若矩形对角线相交所成钝角为120，短边长3.6cm，则对角线的长为( )(A)3.6cm(B)7.2cm(C)1.8cm(D)14.4cm8矩形邻边之比34，对角线长为10cm，则周长为( )(A)14cm(B)28cm(C)20cm(D)22cm9已知AC为矩形ABCD的对角线，则图中1与2一定不相等的是( )(A)(B)(C)(D)综合、运用、诊断一、解答题10已知：如图，ABCD中，AC与BD交于O点，OABOBA(1)求证：四边形ABCD为矩形；(2)作BEAC于E，CFBD于F，求证：BECF11如图，在ABC中，D是BC边上的一点，E是AD的中点，过点A作BC的平行线交BE的延长线于F，且AFDC，连结CF(1)求证：D是BC的中点；(2)如果ABAC，试猜测四边形ADCF的形状，并证明你的结论12如图，矩形ABCD中，AB6cm，BC8cm，若将矩形折叠，使点B与D重合，求折痕EF的长。13已知：如图，在矩形ABCD中，E、F分别是边BC、AB上的点，且EFED，EFED求证：AE平分BAD拓展、探究、思考14如图，在矩形ABCD中，AB2，(1)在边CD上找一点E，使EB平分AEC，并加以说明；(2)若P为BC边上一点，且BP2CP，连结EP并延长交AB的延长线于F求证：ABBF；PAE能否由PFB绕P点按顺时针方向旋转而得到?若能，加以证明，并写出旋转度数；若不能，请说明理由。测试7 矩形1(1)有一个角是直角；(2)都是直角，相等，经过对边中点的直线；(3)平行四边形；对角线相等；三个角25，5 3 460 56C 7B 8B 9D10(1)提示：先证OAOB，推出ACBD；(2)提示：证BOECOF11(1)略；(2)四边形ADCF是矩形 127.513提示：证明BFECED，从而BEDCAB，BAE45，可得AE平分BAD between the requirements. And in the encounter the tedious work, complex things, sometimes take the method of escape, that bridge the boat to the bridge straight , not their own force please find countermeasures, but to wait for the self, the lack of a spirit of hard research.Two, the cause of the problemThrough the analysis, I feel that there are many reasons for these problems.One idea is obsolete. The failure to do system research on the essence o