中学生网络课堂本课配套习题挑战模式1/5
单选题
难度系数：
1.在正方形ABCD中，E为CD上一点，F为BC上一点，且EF=BF+DE，则∠EAF的度数为（ ）
| A: 30° |
| B: 60° |
| C: 45° |
| D: 小于60° |
一次做对，真牛！
+5奖励规则>
- 提示1：DQrlu7bplb9FQuS9v+W+l0JHPURG77yM5piT6K+B4pazQUJH4omM4pazQURG77yIU0FT77yJ5Y+v5b6XQUY9QUfvvIzov5vogIzmsYLor4HilrNBRUfiiYzilrNBRUblj6/lvpfiiKBFQUc94oigRUFG77yM5YaN5rGC5Ye64oigRUFHK+KIoEVBRj05MMKw5Y2z5Y+v6Kej6aKYLiANCg==
- 答案：Qw==
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
本课配套习题挑战模式2/5
单选题
难度系数：
2.如图，在正方形ABCD中，BC=12，∠EBF=45°，若EF=10，则CF的长为（ ）
| A: 6 |
| B: 8 |
| C: 4或8 |
| D: 4或6 |
一次做对，真牛！
+5奖励规则>
- 提示1：IOaKiuKWs0JDRumhuuaXtumSiOaXi+i9rDkwwrDlvpfliLDilrNBQkjvvIzmoLnmja7ml4vovaznmoTmgKfotKjlj6/lvpdCRj1CSO+8jENGPUFI77yM4oigQ0JGPeKIoEFCSO+8jOeEtuWQjuaxguWHuuKIoEVCSD3iiKBFQkY9NDXCsO+8jOWGjeWIqeeUqOKAnOi+ueinkui+ueKAneivgeaYjuKWs0JFRuWSjOKWs0JFSOWFqOetie+8jOagueaNruWFqOetieS4ieinkuW9ouWvueW6lOi+ueebuOetieWPr+W+l0VIPUVG77yM6K6+Q0Y9eO+8jOihqOekuuWHukRG44CBREXvvIznhLblkI7lnKhSdOKWs0RFRuS4reWIqeeUqOWLvuiCoeWumueQhuWIl+WHuuaWueeoi+axguino+WNs+WPry4=
- 答案：RA==
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
本课配套习题挑战模式3/5
单选题
难度系数：
3.如图，正方形ABCD和正方形CGEF的边长分别是2和3，且点B，C，G在同一直线上，M是线段AE的中点，连接MF，则MF的长为（ ）
A:  |
B:  |
C:  |
D:  |
一次做对，真牛！
+5奖励规则>
- 提示1：IOW7tumVv0FE6IezSO+8jOaYk+ivgeKWs0FNSOKJjOKWs0VNRu+8jOW+l0ZNPUhN77yMQUg9RUbvvIzlj4jiiLVESD1BSC1BRO+8jOS4lERGPUNGLUNE77yM6Kej55u06KeS4pazREZI5Y+v5Lul5rGC5b6XRkjnmoTplb/vvIzmoLnmja5GTT1ITeWNs+WPr+ino+mimC4=
- 答案：Qg==
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
本课配套习题挑战模式4/5
单选题
难度系数：
4.如图，正方形ABCE的边长为1，点M、N分别在BC、CD上，且△CMN的周长为2，则△MAN的面积的最小值为（ ）
A:  |
B:  |
| C: |
D:  |
一次做对，真牛！
+5奖励规则>
- 提示1：IOWmguWbvu+8jOW7tumVv0NC6IezTO+8jOS9v0JMPURO77yM5YiZUnTilrNBQkziiYxSdOKWs0FORO+8jOaVhUFMPUFO77yM6L+b6ICM5rGC6K+B4pazQU1O4omM4pazQU1M77yM5Y2z5Y+v5rGC5b6X4oigTUFOPeKIoE1BTD00NcKw6K6+Q009eO+8jENOPXnvvIxNTj1677yM5qC55o2ueDxzdXA+Mjwvc3VwPit5PHN1cD4yPC9zdXA+PXo8c3VwPjI8L3N1cD7vvIzlkox4K3krej0y77yM5pW055CG5qC55o2u4pazPTTvvIh6LTLvvIk8c3VwPjI8L3N1cD4tMzLvvIgxLXrvvIniiaUw5Y+v5Lul6Kej6aKYLg==
- 答案：QQ==
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
本课配套习题挑战模式5/5
单选题
难度系数：
5.如图，梯形ABCD中，AD∥BC，点E在BC上，AE=BE，点F是CD的中点，且AF⊥AB，若AD=2.7，AF=4，AB=6，则CE的长为（ ）
| A: |
B:  |
| C: 2.5 |
| D: 2.3 |
一次做对，真牛！
+5奖励规则>
- 提示1：IOW7tumVv0FG44CBQkPkuqTkuo7ngrlHLiDmoLnmja5BQVPlj6/ku6Xor4HmmI7ilrNBRkTiiYzilrNHRkPvvIzliJlBRz0yQUY9OO+8jENHPUFEPTIuN++8m+agueaNruWLvuiCoeWumueQhu+8jOW+l0JHPTEw77yM5YiZQkM9Ny4z77yb5qC55o2u562J6L655a+5562J6KeS77yM5b6X4oigQkFFPeKIoELvvIzmoLnmja7nrYnop5LnmoTkvZnop5Lnm7jnrYnvvIzlvpfiiKBFQUc94oigQUdF77yM5YiZQUU9R0XvvIzliJlCRT08aW1nIHdpZHRoPTUgaGVpZ2h0PTQyIHNyYz0iaHR0cHM6Ly9wMS5xaW5nZ3VvLmNvbS9HMS9NMDAvOUQvREUvckJBQ0UxT1ZJckRUNzRpbEFBQUJHVThEbEdVNzU5LnBuZyI+Qkc9Ne+8jOi/m+iAjOaxguW+l0NF55qE6ZW/Lg==
- 答案：RA==
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
