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如图,某地夏季中午,当太阳移至房顶上方偏南时,光线与地面成80°角,房屋朝南的窗...
如图,某地夏季中午,当太阳移至房顶上方偏南时,光线与地面成80°角,房屋朝南的窗子高AB=1.8m,要在窗子外面上方安装水平挡光板AC,使午间光线不能直接射入室内,那么挡光板的宽度AC为( )
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103001126545037004/SYS201311030011265450370004_ST/images0.png)
A.1.8tan80°m
B.1.8cos80°m
C.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103001126545037004/SYS201311030011265450370004_ST/0.png)
m
D.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103001126545037004/SYS201311030011265450370004_ST/1.png)
m
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