1/5单选题
难度：
1.已知四边形ABCD，对角线AC与BD互相垂直. 顺次连接其四条边的中点，得到新四边形的形状一定是（）
| A | 梯形 |
| B | 矩形 |
| C | 菱形 |
| D | 正方形 |
- 提示1：
- IOWbm+i+ueW9ouWvueinkue6v+S6kuebuOWeguebtO+8jOi/kOeUqOS4ieinkuW9ouS4reS9jee6v+W5s+ihjOS6juesrOS4iei+ueivgeaYjuWbm+S4quinkumDveaYr+ebtOinkui/kA==
正确答案：Qg==
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
2/5单选题
难度：
2.顺次连结矩形各边的中点所得的菱形面积与矩形面积之比是（ ）
| A | 1：2 |
| B | 1：3 |
| C | 1：4 |
| D | 1：8 |
- 提示1：
- IOWIqeeUqOiPseW9oueahOmdouenr+etieS6juWvueinkue6v+S5mOenr+eahOS4gOWNiu+8jOihqOekuuiPseW9oumdouenr++8mw==
- 提示2：
- IOS4juefqeW9oumdouenr+ihqOi+vuW8j+ebuOavlOaxguWAvO+8mw==
正确答案：QQ==
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
3/5单选题
难度：
3.若顺次连接四边形ABCD的各边中点所得的四边形是菱形，则AC与BD的关系是（ ）
| A | 相等 |
| B | 互相平分 |
| C | 互相垂直 |
| D | 没有明确的位置或大小关系 |
- 提示1：
- IOagueaNruiPseW9oueahOaAp+i0qOWvu+aJvuWQhOi+ueeahOWFs+ezu++8mw==
- 提示2：
- IOagueaNruiPseW9ouWQhOi+ueeahOWFs+ezu+S7peWPiuS4reS9jee6v+eahOaAp+i0qOehruWumuWvueinkue6v+eahOWFs+ezuw==
正确答案：QQ==
PGRpdj7op6PvvJo8aW1nIHdpZHRoPTM0NCBoZWlnaHQ9MTA1IHNyYz0iaHR0cHM6Ly9wMi5xaW5nZ3VvLmNvbS9HMS9NMDAvMDAvNTQvckJBQ0ZGTU1VWmZUQktsVkFBQlRpMnQ2b1QwNjk3LnBuZyIgYWx0PemdkuaenOWtpumZoj48YnI+5Zug5Li6RUZHSOS4uuiPseW9ou+8jOWImUVIPUVGLiA8YnI+5Y+I5Zug5Li6ReOAgUbjgIFH44CBSOS4uuWbm+i+ueS4reeCue+8jOWImUFDPTJFSO+8jEJEPTJGRe+8jOaJgOS7pUJEPUFDLiDmlYXpgIlBLiA8L2Rpdj4=
4/5单选题
难度：
4.
如图，E、F、G、H分别是BD、BC、AC、AD的中点，且AB=CD. 下列结论：
①EG⊥FH，②四边形EFGH是矩形，③HF平分LEHG，④EG=（BC-AD），⑤四边形EFGH是菱形，其中正确的个数是（ ）
| A | 1 |
| B | 2 |
| C | 3 |
| D | 4 |
- 提示1：
- PHA+5qC55o2u5LiJ6KeS5b2i55qE5Lit5L2N57q/5bmz6KGM5LqO56ys5LiJ6L655bm25LiU562J5LqO56ys5LiJ6L6555qE5LiA5Y2K5LiOQUI9Q0Tlj6/lvpflm5vovrnlvaJFRkdI5piv6I+x5b2i77ybPC9wPg==
- 提示2：
- PHA+5qC55o2u6I+x5b2i55qE5a+56KeS57q/5LqS55u45Z6C55u05bmz5YiG77yM5bm25LiU5bmz5YiG5q+P5LiA57uE5a+56KeS55qE5oCn6LSo5a+55ZCE5bCP6aKY6L+b6KGM5Yik5patPC9wPg==
正确答案：Qw==
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
5/5单选题
难度：
5.
如图，矩形ABCD中，AB=6，AD=8，顺次连结各边中点得到四边形A1B1C1D1，再顺次连结四边形A1B1C1D1各边中点得到四边形A2B2C2D2…，依此类推，则四边形A7B7C7D7的周长为（ ）
| A |
|
| B | 10 |
| C | 5 |
| D | 2.5 |
- 提示1：
- PHA+5qC55o2u5Lit5L2N57q/55qE5oCn6LSo5Y+v5b6X5Zub6L655b2iQTxzdWI+MTwvc3ViPkI8c3ViPjE8L3N1Yj5DPHN1Yj4xPC9zdWI+RDxzdWI+MTwvc3ViPuaYr+iPseW9oizlkajplb/kuLoyMDwvcD4=
- 提示2：
- PHA+5o2u5Lit5L2N57q/55qE5oCn6LSo5Y+v5b6X5Zub6L655b2iQTxzdWI+Mjwvc3ViPkI8c3ViPjI8L3N1Yj5DPHN1Yj4yPC9zdWI+RDxzdWI+Mjwvc3ViPuaYr+efqeW9ou+8jOWPr+W+l0E8c3ViPjM8L3N1Yj5EPHN1Yj4zPC9zdWI+PGltZyBzcmM9Imh0dHBzOi8vcDIucWluZ2d1by5jb20vRzEvTTAwLzAwLzU1L3JCQUNGRk1NVVozQVdHdnJBQUFCT2g4VjRmTTIyMC5wbmciIGRhdGEtY2tlLXNhdmVkLXNyYz0iaHR0cHM6Ly9wMi5xaW5nZ3VvLmNvbS9HMS9NMDAvMDAvNTUvckJBQ0ZGTU1VWjNBV0d2ckFBQUJPaDhWNGZNMjIwLnBuZyIgaGVpZ2h0PSI0MiIgd2lkdGg9IjIwIj48L3A+
- 提示3：
- PHA+5Zub6L655b2iQTxzdWI+Mzwvc3ViPkI8c3ViPjM8L3N1Yj5DPHN1Yj4zPC9zdWI+RDxzdWI+Mzwvc3ViPueahOWRqOmVv+aYr++8mjxpbWcgc3JjPSJodHRwczovL3AxLnFpbmdndW8uY29tL0cxL00wMC8yMy80Mi9yQkFDRTFNTVVaM0Jqb1l4QUFBQl8wcnBYQ2c5MTIucG5nIiBkYXRhLWNrZS1zYXZlZC1zcmM9Imh0dHBzOi8vcDEucWluZ2d1by5jb20vRzEvTTAwLzIzLzQyL3JCQUNFMU1NVVozQmpvWXhBQUFCXzBycFhDZzkxMi5wbmciIGhlaWdodD0iNDIiIHdpZHRoPSI2NCI+PC9wPg==
正确答案：RA==
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