中学生网络课堂
本课配套习题挑战模式2/5
单选题
难度系数：
2.如图，矩形ABCD的周长为20cm，两条对角线相交于O点，过O作AC的垂线EF，分别交AD、BC于E、F点，连接EC，则△CDE的周长为( )
| A: 5cm |
| B: 8cm |
| C: 9cm |
| D: 10cm |
一次做对，真牛！
+5奖励规则>
- 提示1：5qC55o2u55+p5b2i55qE5oCn6LSo77yMQU89Q0/vvIznlLFFRuKKpUFD77yM5b6XRUE9RUPvvIzliJnilrNDREXnmoTlkajplb/mmK/nn6nlvaLlkajplb/nmoTkuIDljYrvvI4=
- 答案：RA==
6Kej77ya4oi1QUJDROS4uuefqeW9ou+8jDxicj7iiLRBTz1PQ++8jjxicj7iiLVFRuKKpUFD77yMPGJyPuKItEFFPUVD77yOPGJyPuKItOKWs0NEReeahOWRqOmVvz1DRCtERStFQz1DRCtERStBRT1DRCtBRD0xMO+8iGNt77yJPGJyPuaVhemAiUTvvI4=
本课配套习题挑战模式3/5
单选题
难度系数：
3.如图，在△ABC中，CF⊥AB于F，BE⊥AC于E，M为BC的中点，EF=7，BC=10，则△EFM的周长是( )
| A: 17 |
| B: 21 |
| C: 24 |
| D: 27 |
一次做对，真牛！
+5奖励规则>
- 提示1：5qC55o2uQ0biiqVBQuS6jkbvvIxCReKKpUFD5LqORe+8jE3kuLpCQ+eahOS4reeCue+8jOWIqeeUqOebtOinkuS4ieinkuW9ouaWnOi+ueS4iueahOS4ree6v+etieS6juaWnOi+ueeahOS4gOWNiu+8jOaxguWHukZN5ZKMTUXnmoTplb/vvIzljbPlj6/msYLop6PvvI4=
- 答案：QQ==
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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，矩形ABCD中，E、G为AB、CD边上的点，F为BC的中点，且BE=1，CG=4，BC=4，EF⊥FG，则EG的长为( )
| A: 5 |
| B: 10 |
C:  |
| D: 2 |
一次做对，真牛！
+5奖励规则>
- 提示1：5Zyo55u06KeS5LiJ6KeS5b2iRUJG5ZKM55u06KeS5LiJ6KeS5b2iQ0ZH5Lit77yM5Yip55So5Yu+6IKh5a6a55CG5YiG5Yir5rGC5Ye6RUblkoxGR+eahOmVv+W6pg==
- 提示2：5Yip55So5Yu+6IKh5a6a55CG5rGC5Ye6RUfnmoTplb/luqbljbPlj6/vvI4=
- 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，O是矩形ABCD的对角线AC的中点，M是AD的中点，若AB=5，AD=12，则四边形ABOM的周长为（ ）
| A: 17 |
| B: 18 |
| C: 19 |
| D: 20 |
一次做对，真牛！
+5奖励规则>
- 提示1：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
- 提示2：PHA+5qC55o2u5Yu+6IKh5a6a55CG5Y+v5rGC5Ye6QUPnmoTplb/vvIw8YnI+PC9wPg==
- 提示3：PHA+5Yip55So55u06KeS5LiJ6KeS5b2i5pac6L655LiK55qE5Lit57q/562J5LqO5pac6L6555qE5LiA5Y2K5rGC5Ye6Qk/vvIzov5vogIzmsYLlh7rlm5vovrnlvaJBQk9N55qE5ZGo6ZW/PGJyPjwvcD4=
- 答案：RA==
PHA+4oi1T+aYr+efqeW9okFCQ0TnmoTlr7nop5Lnur9BQ+eahOS4reeCue+8jE3mmK9BROeahOS4reeCue+8jDxicj7iiLTiiKBBQkM94oigRD05MMKw77yMQ0Q9QUI9Ne+8jEJDPUFEPTEy77yMT0E9T0LvvIxPTeS4uuKWs0FDROeahOS4reS9jee6v++8jDxicj7iiLRPTT08c3BhbiBjbGFzcz0ibWF0aHF1aWxsLXJlbmRlcmVkLW1hdGgiIHN0eWxlPSJmb250LXNpemU6MjBweDsiPjxzcGFuIGNsYXNzPSJ0ZXh0YXJlYSI+PHRleHRhcmVhIGRhdGEtY2tlLWVkaXRhYmxlPSIxIiBjb250ZW50ZWRpdGFibGU9ImZhbHNlIj48L3RleHRhcmVhPjwvc3Bhbj48c3BhbiBjbGFzcz0iZnJhY3Rpb24gbm9uLWxlYWYiIG1hdGhxdWlsbC1jb21tYW5kLWlkPSI0Ij48c3BhbiBjbGFzcz0ibnVtZXJhdG9yIiBtYXRocXVpbGwtYmxvY2staWQ9IjUiPjxzcGFuIG1hdGhxdWlsbC1jb21tYW5kLWlkPSI4Ij4xPC9zcGFuPjwvc3Bhbj48c3BhbiBjbGFzcz0iZGVub21pbmF0b3IiIG1hdGhxdWlsbC1ibG9jay1pZD0iNiI+PHNwYW4gbWF0aHF1aWxsLWNvbW1hbmQtaWQ9IjkiPjI8L3NwYW4+PC9zcGFuPjxzcGFuIHN0eWxlPSJkaXNwbGF5OmlubGluZS1ibG9jazt3aWR0aDowIj4mbmJzcDs8L3NwYW4+PC9zcGFuPjwvc3Bhbj48c3Bhbj4gPC9zcGFuPkNEPTIuNe+8jEFDPTEzPGJyPjwvcD48cD7iiLVP5piv55+p5b2iQUJDROeahOWvueinkue6v0FD55qE5Lit54K577yMPGJyPuKItEJPPTxzcGFuIGNsYXNzPSJtYXRocXVpbGwtcmVuZGVyZWQtbWF0aCIgc3R5bGU9ImZvbnQtc2l6ZToyMHB4OyI+PHNwYW4gY2xhc3M9InRleHRhcmVhIj48dGV4dGFyZWEgZGF0YS1ja2UtZWRpdGFibGU9IjEiIGNvbnRlbnRlZGl0YWJsZT0iZmFsc2UiPjwvdGV4dGFyZWE+PC9zcGFuPjxzcGFuIGNsYXNzPSJmcmFjdGlvbiBub24tbGVhZiIgbWF0aHF1aWxsLWNvbW1hbmQtaWQ9IjQiPjxzcGFuIGNsYXNzPSJudW1lcmF0b3IiIG1hdGhxdWlsbC1ibG9jay1pZD0iNSI+PHNwYW4gbWF0aHF1aWxsLWNvbW1hbmQtaWQ9IjgiPjE8L3NwYW4+PC9zcGFuPjxzcGFuIGNsYXNzPSJkZW5vbWluYXRvciIgbWF0aHF1aWxsLWJsb2NrLWlkPSI2Ij48c3BhbiBtYXRocXVpbGwtY29tbWFuZC1pZD0iOSI+Mjwvc3Bhbj48L3NwYW4+PHNwYW4gc3R5bGU9ImRpc3BsYXk6aW5saW5lLWJsb2NrO3dpZHRoOjAiPiZuYnNwOzwvc3Bhbj48L3NwYW4+PC9zcGFuPjxzcGFuPiZuYnNwOzwvc3Bhbj5BQz02LjXvvIw8YnI+4oi05Zub6L655b2iQUJPTeeahOWRqOmVv+S4ukFCK0FNK0JPK09NPTUrNis2LjUrMi41PTIw77yMPGJyPuaVhemAie+8mkTvvI48YnI+PC9wPg==
