(1)45,·····························································································——青夏教育精英家教网—

摘要： (1)45,········································································································ (2)220,············································································································· (3)(图正确

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石板滩东风街十字路口欲设一红绿灯，红灯亮45秒后转换为黄灯，黄灯亮5秒后转换为绿灯，绿灯亮45秒后转换为红灯，一汽车走到这个路口，恰好是绿灯的概率是

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把一副学生用三角板（30°、60°、90°和45°、45°、90°）如图（1）放置在平面直角坐标系中，点A在y轴正半轴上，直角边AC与y轴重合，斜边AD与y轴重合，直角边AE交x轴于F，斜边AB交x轴于G，O是AC中点，AC=8．
（1）把图1中的Rt△AED绕A点顺时针旋转α度（0≤α＜90°）得图2，此时△AGH的面积是10，△AHF的面积是8，分别求F、H、B三点的坐标；
（2）如图3，设∠AHF的平分线和∠AGH的平分线交于点M，∠EFH的平分线和∠FOC的平分线交于点N，当改变α的大小时，∠N+∠M的值是否会改变？若改变，请说明理由；若不改变，请求出其值．