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在初中数学里,旋转是我们经常接触到的一类变换.虽然图形在变换过程中,相关图形的形状与大小不发生改变,但是旋转往往会与隐藏的图形相似或全等联系在一起,因而解答起来并不是很容易.本文试图通过呈现一类与45°定角相关的旋转问题,分析解法、总结结论和揭示规律,旨在交流分享.一、在正方形中,45°角绕顶点旋转,相关线段、面积和为定值例1(2015年十堰中考题)如图1,正方
In junior high school mathematics, rotation is a type of transformation we often encounter.Although the shapes and sizes of the related shapes do not change during the transformation, the rotation tends to be similar or congruent with the hidden shapes, and thus It is not easy to answer it.This paper attempts to present a class of rotation problems related to the 45 ° angle, analyze the solution, summarize the results and reveal the law to exchange and share.First, in the square, 45 ° angle around the vertex rotation, Relevant line, area and for the value of Example 1 (2015 Shiyan test questions) Figure 1, square