1 . 将
的各边按如图所示的方式向内等距缩
,得到
,有以下结论:
I
与
是相似三角形;
Ⅱ
与
是位似三角形.下列判断正确的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e428e7a09732be85c1224e9c8f6a71c5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/048b61a5fb5f420c6d7de88db5bc3aa5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72cb97395ebc5ee1b212afb7a97b985c.png)
I
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72cb97395ebc5ee1b212afb7a97b985c.png)
Ⅱ
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72cb97395ebc5ee1b212afb7a97b985c.png)
A.Ⅰ,Ⅱ都正确 | B.Ⅰ,Ⅱ都不正确 |
C.Ⅰ正确,Ⅱ不正确 | D.Ⅰ不正确,Ⅱ正确 |
您最近一年使用:0次
2 . 如图1,在边长为4的正方形
中,点H为
上一动点,且
,截取
,且
交线段
于M,过M作
的垂线
交
于N.
;
(2)如图2,若点M是
的中点,求
的周长;
(3)在动点H逐渐向点A运动(HB逐渐增大)的过程中,
的周长如何变化?请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fff9613c5a28df46f8c7a142069806b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d82e0e08236295f112b5f3b891bb413d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b0a8588dc60a543ad70d6bc0d263dbd3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b0a8588dc60a543ad70d6bc0d263dbd3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e52a8f07834cbbbe4224962672fbbb2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0114410515a8d139216928adb22b63e.png)
(2)如图2,若点M是
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/999c42a021bdc576f097246b9e64d986.png)
(3)在动点H逐渐向点A运动(HB逐渐增大)的过程中,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/999c42a021bdc576f097246b9e64d986.png)
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3 . 下列命题正确的是( )
A.同圆或等圆中,若![]() ![]() |
B.有一组角相等及两组边成比例的两个三角形相似 |
C.关于x的方程![]() ![]() |
D.二次函数![]() |
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4 . 已知,
是半径为
的
的内接三角形,点
是
的内心,射线
分别交
、
于点
.
,连接
,求证:
;
(2)如图
,
;
若
,求
的长;
若
,求
的值;
(3)如图
,
,射线
分别交
于点
,点
在直线
上方的圆弧上运动,无论点
如何移动,线段
中有一个为定值,请判断是哪一个线段,并求出此定值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d91e07104b699c4012be2d26160976a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3cf9b288c48c73463a2f214f02b6952a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/274cf35acb4a1748d15c39d15a9bea7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/69e40658acadd987ef31344f47bd1450.png)
(2)如图
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c06154cae3bf7a8ce5a1e97a7380875.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e1c9ae241fd78126274c65e17990c88.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54275b7e571660d0a9e0370fbfe5050b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aa2b5e09f8ec785c59900a529390a02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c650fe55b7603f106c53ca2423451c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2fb01d2b57580731c8b807ac8cffc8ba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/929e72e9d26c3bda1fba680ca48cd95d.png)
(3)如图
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ca7d1107389675d32b56ec097464c14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b57fdd2a3642716fcf5100011eb3ec88.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1bb9b29668bafeccf32ca33022e96d16.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e83fd42df335c85bf92b7961b9851977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/91d6e8ea264c32219d738a091d0aa23a.png)
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5 . 如图,
是
的外接圆,
,连接
,延长
交
于点
,交
于点
.
的度数为 度,写出图中一对全等的三角形: ;
(2)求证:
;
(3)若
,试求
的度数.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dc9795efa99b6fb9fdf9778085dab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2c3d2cba96f6f03520c0b3f6e4da03e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2c3d2cba96f6f03520c0b3f6e4da03e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/86a2db6311e228ed33b6c71d0a5918cf.png)
(2)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aeb038e998f6ae01e1166d25f61fff74.png)
(3)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e393a210bd76b5a7499c64b822c3f07b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7cbce11aa19b8bd2bf6ee5a834e005de.png)
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6 . 如图,在
网格图中,每个小正方形的边长均为1,则关于三角形①、②有四个说法,其中正确的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abd4be97adde17423d59d86d18318c2c.png)
A.一定不相似 | B.一定位似 |
C.一定相似,且相似比为![]() | D.一定相似,且相似比为![]() |
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7 . 如果过三角形一个顶点的线段将三角形分成两个三角形,其中的一个三角形与原三角形相似,且该三角形与原三角形的相似比为
,则原三角形叫和谐三角形.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/29/aa8471f6-82f7-4aac-ba56-0df64115169e.png?resizew=400)
(1)如图1,已知
是
中
边上的中线,
,
,求证:
是和谐三角形;
(2)如图2,在5×5的方格纸中,A、B在格点上,请画出一个符合条件的和谐
;
(3)如图3,在(1)的条件下,作
的外接圆
,E是
上一点,且满足
,连接DE,
①设
,
,求y关于x的函数表达式;
②当
时,求
的半径.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/526ddee4ed97b917d9e4cc4542c72a37.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/29/aa8471f6-82f7-4aac-ba56-0df64115169e.png?resizew=400)
(1)如图1,已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0c1ac2e11788860424508ea9e80cf89d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8a7b5adfcac0f46a4cd19da4ebb4a2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
(2)如图2,在5×5的方格纸中,A、B在格点上,请画出一个符合条件的和谐
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
(3)如图3,在(1)的条件下,作
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab2a2834d80ff574e79eae8ca8d4e94f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c6743d46804193a68ed10d20a68609f.png)
①设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61c34eff4d793873d9e812d75d90fd10.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e83115ca0edf2fedb181bb960f3efde.png)
②当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/542b5bc10c7341c04c22244f3ec16e6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
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8 . 如图,在平面直角坐标系中,已知
,
,
,作
轴,垂足为点D,连接
,
,
.求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6f2b1f4120365cb6ee4925fe417563f9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/557437a8641a61bf64c1e40f2bbf72a6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c6810da77bafee796a54b2e31f7d729e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2634263d383b0487281fdcf6fe3cc625.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1d5db297a484eed1457626386ff2b0d.png)
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9 . 数学实践活动课上,小明和小强分别剪了一对三角形,他们经过测量得到相关数据,并标记在图形上.如图,对于他们剪的两组三角形的说法,正确的是( )
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/3/f4a1abfe-045f-454f-830c-69d513a2e4df.png?resizew=435)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/3/f4a1abfe-045f-454f-830c-69d513a2e4df.png?resizew=435)
A.都相似 | B.只有图①相似 | C.只有图②相似 | D.都不相似 |
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10 . 在数学史上,有很多著名的几何图形用来验证数学知识的产生过程.如图所示的图案,是由一连串公共顶点为O的直角三角形拼接而成,若
,则图中直角三角形之间存在的变换关系是( )
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/24/d9851d07-0dea-4311-a5db-108e99122598.jpg?resizew=218)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad7761a7898ab2e9081ebc13f648ac5f.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/24/d9851d07-0dea-4311-a5db-108e99122598.jpg?resizew=218)
A.图形的平移 | B.图形的旋转 | C.图形的全等 | D.图形的相似 |
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