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.如图，直线l是一条河，A、B两地相距10km，A、B两地到l的距离分别为8km、14km，欲在l上的某点M处修建一个水泵站，向A、B两地供水，现有如下四种铺设方案，图中实线表示铺设的管道，则铺设的管道最短的是（ ）
A:  |
B:  |
C:  |
D:  |
一次做对，真牛！
+5奖励规则>
- 提示1：5L2c54K5QeWFs+S6juebtOe6v2znmoTlr7nnp7DngrnvvIzlho3miorlr7nnp7DngrnkuI7ngrlC6L+e5o6l77yM5qC55o2u6L205a+556ew56Gu5a6a5pyA55+t6Lev57q/6Zeu6aKY77yM5Lqk54K55Y2z5Li65omA5rGC54K5Te+8jg==
- 答案：Qg==
6Kej77ya5qC55o2u6L205a+556ew56Gu5a6a5pyA55+t6Lev57q/6Zeu6aKY77yMQumAiemhueWbvuW9ouaWueahiOespuWQiO+8jjxicj7mlYXpgIlC77yO
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中，AB=20，BC=10，若在AB、AC上各取一点N、M，使得BM+MN的值最小，这个最小值为（ ）
| A: 12 |
B: 10 |
| C: 16 |
| D: 20 |
一次做对，真牛！
+5奖励规则>
- 提示1：5L2cQuWFs+S6jkFD55qE5a+556ew54K5QuKAsu+8jOi/nkFC4oCy77yM5YiZTueCueWFs+S6jkFD55qE5a+556ew54K5TuKAsuWcqEFC4oCy5LiK77yM6L+Z5pe277yMQuWIsE3liLBO55qE5pyA5bCP5YC8562J5LqOQuKGkk3ihpJO4oCy55qE5pyA5bCP5YC877yM562J5LqOQuWIsEFC4oCy55qE6Led56a7QkjigLI=
- 提示2：55Sx5LiJ6KeS5b2i55qE6Z2i56ev5YWs5byP5Y+v5rGC5Ye6UzxzdWI+4pazQUJQPC9zdWI+55qE5YC877yM5qC55o2u5a+556ew55qE5oCn6LSo5Y+v55+l4oigUEFDPeKIoEJBQz3iiKBQQ0HvvIzliKnnlKjli77ogqHlrprnkIblj6/msYLlh7pQQeeahOWAvO+8jOWGjeeUsVM8c3ViPuKWs0FCUDwvc3ViPj08aW1nIHdpZHRoPTYgaGVpZ2h0PTQyIHNyYz0iaHR0cHM6Ly9wMS5xaW5nZ3VvLmNvbS9HMS9NMDAvNkUvMTUvckJBQ0oxVV9SMTNoOXNkWUFBQUJIR2pNakYwNzU1LnBuZyI+UEEmIzgyMjY7QkjigLLljbPlj6/msYLop6PvvI4=
- 答案：Qw==
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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，菱形ABCD中，对角线AC=8，BD=6，点E，F分别是边AB，BC的中点，点P在AC上运动，在运动过程中，存在PE+PF的最小值，则这个最小值是（ ）
| A: 3 |
| B: 4 |
| C: 5 |
| D: 6 |
一次做对，真牛！
+5奖励规则>
- 提示1：5qC55o2u6I+x5b2i55qE5a+56KeS57q/5LqS55u45Z6C55u05bmz5YiG5Y+v5b6XQUPiiqVCRO+8jEFPPTxpbWcgd2lkdGg9NiBoZWlnaHQ9NDIgc3JjPSJodHRwczovL3AxLnFpbmdndW8uY29tL0cxL00wMC82RC9FMS9yQkFDSmxVX1NTSEFLUzBnQUFBQkhHak1qRjAyODEucG5nIj5BQ++8jEJPPTxpbWcgd2lkdGg9NiBoZWlnaHQ9NDIgc3JjPSJodHRwczovL3AxLnFpbmdndW8uY29tL0cxL00wMC82RC9FMS9yQkFDSmxVX1NTSEFLUzBnQUFBQkhHak1qRjAyODEucG5nIj5CRO+8jOWIqeeUqOWLvuiCoeWumueQhuWIl+W8j+axguWHukFC
- 提示2：5L2c54K5ReWFs+S6jkFD55qE5a+556ew54K5ReKAsu+8jOagueaNrui9tOWvueensOehruWumuacgOefrei3r+e6v+mXrumimO+8jOi/nuaOpUXigLJG5LiOQUPnmoTkuqTngrnljbPkuLrmiYDmsYLnmoRQRStQRuacgOWwj+WAvOeahOeCuVA=
- 提示3：5YaN5qC55o2u6I+x5b2i55qE6L205a+556ew5oCn5Y+v55+lReKAsuS4ukFE55qE5Lit54K577yMReKAskbnmoTplb/nrYnkuo7oj7HlvaLnmoTovrnplb/vvIzku47ogIzlvpfop6PvvI4=
- 答案：Qw==
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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，等边△ABC的边长为4，AD是BC边上的中线，F是AD边上的动点，E是AC边上一点，若AE=2，当EF+CF取得最小值时，则∠ECF的度数为（ ）
| A: 15° |
| B: 22.5° |
| C: 30° |
| D: 45° |
一次做对，真牛！
+5奖励规则>
- 提示1：6L+HReS9nEVN4oilQkPvvIzkuqRBROS6jk7vvIzov57mjqVDTeS6pEFE5LqORu+8jOi/nuaOpUVG77yM5o6o5Ye6TeS4ukFC5Lit54K577yM5rGC5Ye6ReWSjE3lhbPkuo5BROWvueensO+8jOagueaNruetiei+ueS4ieinkuW9ouaAp+i0qOaxguWHuuKIoEFDTe+8jOWNs+WPr+axguWHuuetlOahiO+8jg==
- 答案：Qw==
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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，AB⊥BC，AD⊥DC，∠BAD=110°，在BC、CD上分别找一点M、N，当△AMN周长最小时，∠MAN的度数为（ ）
| A: 30° |
| B: 40° |
| C: 50° |
| D: 60° |
一次做对，真牛！
+5奖励规则>
- 提示1：5qC55o2u6KaB5L2/4pazQU1O55qE5ZGo6ZW/5pyA5bCP77yM5Y2z5Yip55So54K555qE5a+556ew77yM5L2/5LiJ6KeS5b2i55qE5LiJ6L655Zyo5ZCM5LiA55u057q/5LiK77yM5L2c5Ye6QeWFs+S6jkJD5ZKMQ0TnmoTlr7nnp7DngrlB4oCy77yMQeKAs++8jOWNs+WPr+W+l+WHuuKIoEFB4oCyTSviiKBB4oCzPeKIoEhBQeKAsj03MMKw
- 提示2：6L+b6ICM5b6X5Ye64oigTUFCK+KIoE5BRD03MMKw77yM5Y2z5Y+v5b6X5Ye6562U5qGI77yO
- 答案：Qg==
6Kej77ya5L2cQeWFs+S6jkJD5ZKMQ0TnmoTlr7nnp7DngrlB4oCy77yMQeKAs++8jOi/nuaOpUHigLJB4oCz77yM5LqkQkPkuo5N77yM5LqkQ0Tkuo5O77yM5YiZQeKAskHigLPljbPkuLrilrNBTU7nmoTlkajplb/mnIDlsI/lgLzvvIzkvZxEQeW7tumVv+e6v0FI77yM77yOPGJyPuKIteKIoERBQj0xMTDCsO+8jDxicj7iiLTiiKBIQUHigLI9NzDCsO+8jDxicj7iiLTiiKBBQeKAsk0r4oigQeKAsz3iiKBIQUHigLI9NzDCsO+8jDxicj7iiLXiiKBNQeKAskE94oigTUFC77yM4oigTkFEPeKIoEHigLPvvIw8YnI+4oi04oigTUFCK+KIoE5BRD03MMKw77yMPGJyPuKItOKIoE1BTj0xMTDCsC03MMKwPTQwwrDvvI48YnI+5pWF6YCJQu+8jg==
