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1、精心整理2012 年全国中考数学试题分类解析汇编(159 套 63 专题）专题 43：平行四边形一、选择题1.（2012 广东佛山 3 分）依次连接任意四边形各边的中点，得到一个特殊图形（可认为是一般四边形的性质），则这个图形一定是【】A平行四边形B矩形C菱形D梯形【答案】A。【考点】三角形中位线定理，平行四边形的判定。【分析】根据题意画出图形，如右图所示：连接 AC，四边形 ABCD 各边中点是 E、F、G、H，HG AC，HG=12AC，EF AC，EF=12AC。EF=GH，EF GH。四边形 EFGH 是平行四边形。由于四边形 EFGH 是平行四边形，它就不可能是梯形；同时由于是任意四
2、边形，所以 AC=BD或 AC BD不一定成立，从而得不到矩形或菱形的判断。故选 A。2.（2012 浙江杭州3 分）已知平行四边形ABCD 中，B=4 A，则 C=【】A18B 36C72D144【答案】B。【考点】平行四边形的性质，平行线的性质。【分析】由平行四边形性质求出 C=A，BC AD，推出A+B=180 ，求出A 的度数，即可求出C：四边形ABCD 是平行四边形，C=A，BC AD。A+B=180。B=4 A，A=36。C=A=36。故选B。3.（2012 湖北武汉 3 分）在面积为 15 的平行四边形 ABCD 中，过点 A作 AE垂直于直线 BC于点 E，作 AF垂直于直线
3、CD于点 F，若 AB 5，BC 6，则 CE CF的值为【】精心整理A1111 32B1111 32C 1111 32或 1111 32D 1111 32或 132【答案】C。【考点】平行四边形的性质和面积，勾股定理。【分析】依题意，有如图的两种情况。设BE=x，DF=y。如图 1，由 AB 5，BE=x，得222AEABBE25x。由平行四边形 ABCD 的面积为 15，BC 6，得2625x=15，解得5 3x=2（负数舍去）。由 BC 6，DF=y，得222AFADDF36y。由 平 行 四 边 形ABCD的 面 积 为15，AB 5，得253 6y=1 5，解得y=3 3（负数舍去）
4、。CE CF=（65 32）（53 3）=1111 32。如图 2，同理可得 BE=5 32，DF=3 3。CE CF=（65 32）（53 3）=1111 32。故选 C。4.（2012 湖南益阳4 分）如图，点A是直线 l 外一点，在l 上取两点B、C，分别以A、C为圆心，BC、AB长为半径画弧，两弧交于点D，分别连接AB、AD、CD，则四边形ABCD 一定是【】A平行四边形B矩形C菱形D梯形【答案】A。【考点】作图（复杂作图），平行四边形的判定。【分析】别以 A、C为圆心，BC、AB长为半径画弧，两弧交于点D，AD=BC，AB=CD。四边形ABCD 是平行四边形（两组对边分别相等的四边形
5、是平行四边形）。故选 A。5.（2012四川广元 3 分）若以 A（-0.5，0），B（2，0），C（0，1）三点为顶点要画平行四边形，则第四个顶点不可能在【】A.第一象限 B.第二象限 C.第三象限 D.第四象限文档编码:CK7A7D8P4Z10 HU7N7X4O7N1 ZK3R7P7L7K3文档编码:CK7A7D8P4Z10 HU7N7X4O7N1 ZK3R7P7L7K3文档编码:CK7A7D8P4Z10 HU7N7X4O7N1 ZK3R7P7L7K3文档编码:CK7A7D8P4Z10 HU7N7X4O7N1 ZK3R7P7L7K3文档编码:CK7A7D8P4Z10 HU7N7X4O7N1
6、 ZK3R7P7L7K3文档编码:CK7A7D8P4Z10 HU7N7X4O7N1 ZK3R7P7L7K3文档编码:CK7A7D8P4Z10 HU7N7X4O7N1 ZK3R7P7L7K3文档编码:CK7A7D8P4Z10 HU7N7X4O7N1 ZK3R7P7L7K3文档编码:CK7A7D8P4Z10 HU7N7X4O7N1 ZK3R7P7L7K3文档编码:CK7A7D8P4Z10 HU7N7X4O7N1 ZK3R7P7L7K3文档编码:CK7A7D8P4Z10 HU7N7X4O7N1 ZK3R7P7L7K3文档编码:CK7A7D8P4Z10 HU7N7X4O7N1 ZK3R7P7L7K3文
7、档编码:CK7A7D8P4Z10 HU7N7X4O7N1 ZK3R7P7L7K3文档编码:CK7A7D8P4Z10 HU7N7X4O7N1 ZK3R7P7L7K3文档编码:CK7A7D8P4Z10 HU7N7X4O7N1 ZK3R7P7L7K3文档编码:CK7A7D8P4Z10 HU7N7X4O7N1 ZK3R7P7L7K3文档编码:CK7A7D8P4Z10 HU7N7X4O7N1 ZK3R7P7L7K3文档编码:CK7A7D8P4Z10 HU7N7X4O7N1 ZK3R7P7L7K3文档编码:CK7A7D8P4Z10 HU7N7X4O7N1 ZK3R7P7L7K3文档编码:CK7A7D8P4
8、Z10 HU7N7X4O7N1 ZK3R7P7L7K3文档编码:CK7A7D8P4Z10 HU7N7X4O7N1 ZK3R7P7L7K3文档编码:CK7A7D8P4Z10 HU7N7X4O7N1 ZK3R7P7L7K3文档编码:CK7A7D8P4Z10 HU7N7X4O7N1 ZK3R7P7L7K3文档编码:CK7A7D8P4Z10 HU7N7X4O7N1 ZK3R7P7L7K3文档编码:CK7A7D8P4Z10 HU7N7X4O7N1 ZK3R7P7L7K3文档编码:CK7A7D8P4Z10 HU7N7X4O7N1 ZK3R7P7L7K3文档编码:CK7A7D8P4Z10 HU7N7X4O7
9、N1 ZK3R7P7L7K3文档编码:CK7A7D8P4Z10 HU7N7X4O7N1 ZK3R7P7L7K3文档编码:CK7A7D8P4Z10 HU7N7X4O7N1 ZK3R7P7L7K3文档编码:CK7A7D8P4Z10 HU7N7X4O7N1 ZK3R7P7L7K3文档编码:CK7A7D8P4Z10 HU7N7X4O7N1 ZK3R7P7L7K3文档编码:CK7A7D8P4Z10 HU7N7X4O7N1 ZK3R7P7L7K3文档编码:CK7A7D8P4Z10 HU7N7X4O7N1 ZK3R7P7L7K3文档编码:CK7A7D8P4Z10 HU7N7X4O7N1 ZK3R7P7L7K
10、3文档编码:CK7A7D8P4Z10 HU7N7X4O7N1 ZK3R7P7L7K3文档编码:CK7A7D8P4Z10 HU7N7X4O7N1 ZK3R7P7L7K3文档编码:CK7A7D8P4Z10 HU7N7X4O7N1 ZK3R7P7L7K3文档编码:CK7A7D8P4Z10 HU7N7X4O7N1 ZK3R7P7L7K3文档编码:CK7A7D8P4Z10 HU7N7X4O7N1 ZK3R7P7L7K3文档编码:CK7A7D8P4Z10 HU7N7X4O7N1 ZK3R7P7L7K3文档编码:CK7A7D8P4Z10 HU7N7X4O7N1 ZK3R7P7L7K3文档编码:CK7A7D8
11、P4Z10 HU7N7X4O7N1 ZK3R7P7L7K3文档编码:CK7A7D8P4Z10 HU7N7X4O7N1 ZK3R7P7L7K3文档编码:CK7A7D8P4Z10 HU7N7X4O7N1 ZK3R7P7L7K3文档编码:CK7A7D8P4Z10 HU7N7X4O7N1 ZK3R7P7L7K3文档编码:CK7A7D8P4Z10 HU7N7X4O7N1 ZK3R7P7L7K3文档编码:CK7A7D8P4Z10 HU7N7X4O7N1 ZK3R7P7L7K3文档编码:CK7A7D8P4Z10 HU7N7X4O7N1 ZK3R7P7L7K3精心整理【答案】C。【考点】平行四边形的判定，坐标
12、与图形性质。【分析】根据题意画出图形，如图所示：分三种情况考虑：以 CB 为对角线作平行四边形ABD1C，此时第四个顶点D1落在第一象限；以 AC为对角线作平行四边形ABCD2，此时第四个顶点D2落在第二象限；以 AB为对角线作平行四边形ACBD3，此时第四个顶点D3落在第四象限。则第四个顶点不可能落在第三象限。故选C。6.（2012 四川德阳 3 分）如图，点 D是ABC的边 AB的延长线上一点，点F 是边 BC上的一个动点（不与点 B重合）.以 BD、BF为邻边作平行四边形BDEF，又 APBE（点 P、E在直线 AB的同侧），如果BDB14A，那么 PBC 的面积与 ABC面积之比为【】
13、A.41B.53C.51D.43【答案】D。【考点】平行四边形的判定和性质。【分析】过点 P作 PH BC交 AB于 H，连接 CH，PF，PE。APBE，四边形 APEB 是平行四边形。PEAB。，四边形BDEF是平行四边形，EFBD。EF AB。P，E，F 共线。设 BD=a，1BDAB4，PE=AB=4a。PF=PE EF=3a。PH BC，SHBC=SPBC。PF AB，四边形BFPH是平行四边形。BH=PF=3a。SHBC：SABC=BH：AB=3a：4a=3：4，SPBC：SABC=3：4。故选 D。7.（2012四川巴中 3 分）不能判定一个四边形是平行四边形的条件是【】A.两组
14、对边分别平行B.一组对边平行，另一组对边相等C.一组对边平行且相等D.两组对边分别相等【答案】B。文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J
15、3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK
16、2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J
17、3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK
18、2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J
19、3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK
20、2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5精心整理【考点】平行四边形的判定【分析】根据平行四边形的判定：两组对边分别平行的四边形是平行四边形；两组对边分别相等的四边形是平行四边形；两组对角分别相等的四边形是平行四边形；对角线互相平分的四边形是平行四边形；一组对边平行且相等的四边形是平行四边形。A、D、C
21、均符合是平行四边形的条件，B则不能判定是平行四边形。故选B。8.（2012 四川自贡3 分）如图，在平行四边形ABCD 中，AD=5，AB=3，AE平分 BAD交 BC边于点 E，则线段BE，EC的长度分别为【】A2 和 3 B3 和 2 C4 和 1 D1 和 4【答案】B。【考点】平行四边形的性质，平行的性质，等腰三角形的判定和性质。【分析】AE平分 BAD，BAE=DAE。四边形ABCD 是平行四边形，AD BC。DAE=AEB。BAE=BEA。AB=BE=3。EC=AD BE=2。故选 B。9.（2012辽宁阜新 3 分）如图，四边形 ABCD 是平行四边形，BE平分ABC，CF平分B
22、CD，BE、CF交于点 G 若使EFD14A，那么平行四边形ABCD 应满足的条件是【】AABC=60 B AB：BC=1：4C AB：BC=5：2DAB：BC=5：8【答案】D。【考点】平行四边形的性质，平行的性质，等腰三角形的判定。【分析】四边形 ABCD 是平行四边形，AD BC，AB=CD，AD=BC。AEB=EBC。又 BE平分ABC，ABE=EBC。ABE=AEB。AB=AE。同理可得：DC=DF。AE=DF。AE EF=DE EF，即 AF=DE。当1EFAD4时，设 EF=x，则 AD=BC=4x。AF=DE=14（AD EF）=1.5x。AE=AB=AF+EF=2.5x。AB
23、：BC=2.5：4=5：8。以上各步可逆，当 AB：BC=2.5：4=5：8 时，1EFAD4。故选 D。文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV
24、3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P
25、7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV
26、3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P
27、7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV
28、3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P
29、7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5精心整理10.（2012 山东聊城3 分）如图，四边形ABCD 是平行四边形，点E在边 BC上，如果点F 是边 AD上的点，那么CDF与ABE不一定全等的条件是【】ADF=BE BAF=CE CCF=AE DCF AE【答案】C。【考点】平行四边形的性质
30、，全等三角形的判定。【分析】根据平行四边形的性质和全等三角形的判定方法逐项分析即可：A、当 DF=BE时，由平行四边形的性质可得：AB=CD，B=D，利用 SAS可判定CDF ABE；B、当 AF=CE时，由平行四边形的性质可得：BE=DF，AB=CD，B=D，利用SAS可判定 CDF ABE；C、当 CF=AE时，由平行四边形的性质可得：AB=CD，B=D，利用SSA不能可判定 CDF ABE；D、当 CF AE时，由平行四边形的性质可得：AB=CD，B=D，AEB=CFD，利用 AAS可判定 CDF ABE。故选 C。11.（2012 山东泰安3 分）如图，在平行四边形ABCD中，过点C的
31、直线 CE AB，垂足为E，若 EAD=53，则BCE的度数为【】A53B 37C47D123【答案】B。【考点】平行四边形的性质，对项角的性质，平行的性质。【分析】设 CE与 AD相交于点F。在平行四边形ABCD 中，过点 C的直线 CE AB，E=90，EAD=53，EFA=90 53=37。DFC=37四边形ABCD 是平行四边形，AD BC。BCE=DFC=37。故选B。12.（2012 广西南宁 3 分）如图，在平行四边形ABCD 中，AB=3cm，BC=5cm，对角线 AC，BD相交于点 O，则 OA的取值范围是【】A2cm OA 5cmB2cm OA 8cmC 1cm OA 4c
32、mD3cm OA 8cm【答案】C。【考点】平行四边形的性质，三角形三边关系。【分析】平行四边形 ABCD 中，AB=3cm，BC=5cm，OA=OC=12AC（平行四边形对角线互相平分），文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:
33、CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N
34、7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:
35、CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N
36、7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:
37、CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N
38、7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5精心整理BC AB AC BC AB（三角形三边关系），即 2cm AC 8cm。1cm OA 4cm。故选 C。13.（2012 内蒙古包头 3 分）如图，过口 ABC
39、D 的对角线 BD上一点 M分别作平行四边形两边的平行线 EF与 GH，那么图中的 口 AEMG 的面积 S1与口 HCFG 的面积 S2的大小关系是【】A.S1S2B.S1S2C.S1=S2D.2S1=S2【答案】C。【考点】平行四边形的判定和性质。【分析】易知，四边形 BHME 和 MFDG 都是平行四边形。平行四边形的对角线把平行四边形分成了两个面积相等的三角形，ABDBCDEBMBHMGMDDMFS SS SS S，。ABDEBMGMDBCDBHMDMFSSS S S S，即 S1=S2。故选 C。14.（2012黑龙江绥化 3 分）如图，在平行四边形ABCD 中，E是 CD上的一点，
40、DE：EC=2：3，连接 AE、BE、BD，且 AE、BD交于点 F，则 SDEF：SEBF：SABF=【】A2：5：25B4：9：25C 2：3：5D4：10：25【答案】D。【考点】平行四边形的性质，相似三角形的判定和性质。【分析】由 DE：EC=2：3 得 DE：DC=2：5，根据平行四边形对边相等的性质，得DE：AB=2：5 由平行四边形对边平行的性质易得DFE BFADF：FB=DE：AB=2：5，SDEF：SABF=4：25。又SDEF和 SEBF是等高三角形，且DF：FB=2：5，SDEF：SEBF=2：5=4：10。SDEF：SEBF：SABF=4：10：25。故选 D。二、填
41、空题1.（2012 广东汕头4 分）如图，在?ABCD 中，AD=2，AB=4，A=30，以点A为圆心，AD的长为半径画弧交AB于点 E，连接 CE，则阴影部分的面积是（结果保留）【答案】133。【考点】平行四边形的性质，扇形面积的计算【分析】过 D点作 DF AB于点 F。AD=2，AB=4，A=30，文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P
42、7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV
43、3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P
44、7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV
45、3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P
46、7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV
47、3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5精心整理DF=AD?sin30=1，EB=AB AE=
48、2。阴影部分的面积=平行四边形ABCD 的面积扇形ADE面积三角形CBE的面积=2302114 12 1336023。2.（2012 浙江衢州4 分）如图，平行四边形ABCD 中，E是 CD的延长线上一点，BE与 AD交于点 F，CD=2DE 若DEF的面积为a，则平行四边形ABCD 的面积为（用 a 的代数式表示）【答案】12a。【考点】平行四边形的性质，相似三角形的判定和性质。【分析】四边形ABCD 是平行四边形，AB CD，AD BC，AB=CD，DEF CEB，DEF ABF。SDEF：SCEB=（DE：CE）2，SDEF：SABF=（DE：AB）2，CD=2DE，DE：CE=1：3，
49、DE：AB=1：2，SDEF=a，SCBE=9a，SABF=4a，S四边形 BCDF=SCEBSDEF=8a。S?ABCD=S四边形 BCDF+SABF=8a+4a=12a。3.（2012 江苏南京 2 分）如图，在平行四边形 ABCD 中，AD=10cm，CD=6cm，E为 AD上一点，且 BE=BC，CE=CD，则 DE=cm【答案】2.5。【考点】平行四边形的性质，平行的性质，等腰三角形的性质，相似三角形的判定和性质。【分析】四边形 ABCD 是平行四边形，AD=10cm，CD=5cm，BC=AD=10cm，AD BC，2=3。BE=BC，CE=CD，BE=BC=10cm，CE=CD=5
50、cm，1=2，3=D。1=2=3=D。BCE CDE。BCCECDDE，即1055DE，解得 DE=2.5cm。4.（2012 江苏镇江2 分）如图，E是平行四边形ABCD 的边 CD上一点，连接AE并延长交 BC的延长线于点F，且AD=4，CE1AB3，则 CF的长为。【答案】2。【考点】平行四边形的性质，相似三角形的判定和性质的。【分析】四边形 ABCD 是平行四边形，AB DC，BC=AD=4。CEF ABF。CECFABBF。又CE1AB3，BF=BC+CF=4+CF，CF14CF3，解得 CF=2。文档编码:CV3T3J3X1G5 HV3S6X3N7P7 ZK2X6Y4I1F5文档编