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测量问题一般要涉及到仰角、俯角、方位角、坡度(坡比)等概念.它是解直角三角形的重点,也是中考的热点.本文以经典测量图为母图,通过几何变换(平移、旋转、对称),将测量问题以及水利建筑问题串起来,揭示各种问题的内在联系.经典图形及其解读如图1所示,点B、C、D在同一条直线上,AD⊥BD,α和β是特殊角(如30°,45°,60°),该图可用在测量物体的高度等实际问题中.命题角度:角度一:已知BC的长及α,β的大小,求高AD;
The measurement problem generally involves the concept of elevation angle, depression angle, azimuth angle, slope (slope ratio), etc. It is the focus of the right triangle, but also the hot spot in the test.With the classic measurement graph as the mother graph, through the geometric transformation (translation, rotation , Symmetry), the measurement problems and water conservancy building problems string together to reveal the internal relations of various problems.Classical graphics and its interpretation as shown in Figure 1, points B, C, D on the same line, AD⊥BD, α And β is a special angle (such as 30 °, 45 °, 60 °), the graph can be used in the measurement of the actual height of objects such as proposition angle: Angle 1: known BC length and α, β size, AD;