茗阳阁位于河南省信阳市狮河区茶韵路一号,建成于2007年4月29日.是一栋由多种中国建筑元素,由雕栏飞檐、勾心斗角、斗拱图腾等多种形式的中国古代建筑元素汇聚而成,具有浓郁地方古建筑特色的塔式阁楼.茗阳阁是信阳新建的城市文化与形象的代表建筑之一,同时茗阳阁旁的风景也是优美至极.某数学课外兴趣小组为了测量建在山丘
![](http://math.21cnjy.com/mml2svg?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmrow%3E%3Cmi%3ED%3C%2Fmi%3E%3Cmi%3EE%3C%2Fmi%3E%3C%2Fmrow%3E%3C%2Fmath%3E)
上的茗阳阁
![](http://math.21cnjy.com/mml2svg?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmrow%3E%3Cmi%3EC%3C%2Fmi%3E%3Cmi%3ED%3C%2Fmi%3E%3C%2Fmrow%3E%3C%2Fmath%3E)
的高度,在山脚下的广场上
![](http://math.21cnjy.com/mml2svg?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi%3EA%3C%2Fmi%3E%3C%2Fmath%3E)
处测得建筑物点
![](http://math.21cnjy.com/mml2svg?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi%3ED%3C%2Fmi%3E%3C%2Fmath%3E)
(即山顶)的仰角为20°,沿水平方向前进20米到达
![](http://math.21cnjy.com/mml2svg?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi%3EB%3C%2Fmi%3E%3C%2Fmath%3E)
点,测得建筑物顶部
![](http://math.21cnjy.com/mml2svg?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi%3EC%3C%2Fmi%3E%3C%2Fmath%3E)
点的仰角为45°,已知山丘
![](http://math.21cnjy.com/mml2svg?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmrow%3E%3Cmi%3ED%3C%2Fmi%3E%3Cmi%3EE%3C%2Fmi%3E%3C%2Fmrow%3E%3C%2Fmath%3E)
高37.69米.求塔的高度
![](http://math.21cnjy.com/mml2svg?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmrow%3E%3Cmi%3EC%3C%2Fmi%3E%3Cmi%3ED%3C%2Fmi%3E%3C%2Fmrow%3E%3C%2Fmath%3E)
.(结果精确到1米,参考数据:
![](http://math.21cnjy.com/mml2svg?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmrow%3E%3Cmtext%3Esin%3C%2Fmtext%3E%3Cmsup%3E%3Cmrow%3E%3Cmn%3E20%3C%2Fmn%3E%3C%2Fmrow%3E%3Cmn%3E0%3C%2Fmn%3E%3C%2Fmsup%3E%3Cmo%3E%E2%89%88%3C%2Fmo%3E%3Cmn%3E0.34%3C%2Fmn%3E%3Cmo%3E++%EF%BC%8C+%3C%2Fmo%3E%3Cmtext%3Ecos%3C%2Fmtext%3E%3Cmsup%3E%3Cmrow%3E%3Cmn%3E20%3C%2Fmn%3E%3C%2Fmrow%3E%3Cmn%3E0%3C%2Fmn%3E%3C%2Fmsup%3E%3Cmo%3E%E2%89%88%3C%2Fmo%3E%3Cmn%3E0.94%3C%2Fmn%3E%3Cmo%3E++%EF%BC%8C+%3C%2Fmo%3E%3Cmtext%3Etan%3C%2Fmtext%3E%3Cmsup%3E%3Cmrow%3E%3Cmn%3E20%3C%2Fmn%3E%3C%2Fmrow%3E%3Cmn%3E0%3C%2Fmn%3E%3C%2Fmsup%3E%3Cmo%3E%E2%89%88%3C%2Fmo%3E%3Cmn%3E0.36%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmath%3E)
)