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对同学们来说,手中的直尺和三角板是再熟悉不过的学习工具了.你知道吗?两者的结合,却能组合出许多中考试题呢!现介绍几例,供参考.一、求一个角的大小例1(2014年·巴彦淖尔)把一根直尺与一块三角尺如图1所示放置.若∠1=55°,则∠2的度数为().A.125°B.135°C.145°D.155°分析:如图1,由三角形的内角和等于180°,即可求得∠ACB的度数.又由邻补角的定义,可求得∠BCD的度数.然后由两直
For students, the hands of ruler and triangle board is a familiar learning tool. You know? The combination of the two, but can be combined with many of the senior high school exam questions! Here are a few examples for reference. The size of a corner Example 1 (Bayannuir 2014) Place a ruler and a ruler as shown in Figure 1. If ∠1 = 55 °, the degree of ∠2 is () .A.125 ° B.135 ° C.145 ° D.155 ° Analysis: As shown in Fig. 1, the degree of ∠ACB can be obtained from the internal angle of the triangle and equal to 180 °, and the definition of the adjacent angle can be obtained as ∠BCD Degrees and then by two straight