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用三角法证几何题可以不添辅助线或少添辅助线,降低证明难度,同时又能开拓思路,从而提高证题能力.在初中用三角法证几何题是以直角三角形为基础,以锐角三角函数为主要手段,通过运算或用运算代替推理进行证明,它的证题步骤是:(1)选择或构造直角三角形;(2)设某角为α,用一些线段和α的三角函数表示其他的线段,建立起边角关系等式.
With the trigonometric forensic geometry problem, you can not add auxiliary lines or add less auxiliary lines to reduce the difficulty of proof, and at the same time, you can develop ideas to improve the ability of the questions. In the junior high school, the trigonometric forensic geometry questions are based on right-angled triangles and are based on acute angles. The trigonometric function is the main means. It is proved by operations or by using operations instead of reasoning. Its steps are: (1) selecting or constructing a right-angled triangle; (2) setting an angle to be α, represented by some line segments and the trigonometric function of α Other line segments establish equations for corner relations.