平行线与三角形是初中几何中两个重要的基本图形,也是中考常考的知识点,以此为背景的试题随处可见,现结合部分中考试题进行说明,供同学们学习参考.一、考查"三线八角例1(2014·海南)如图1,已知AB∥CD,与∠1是同位角的角是().A.∠2 B.∠3C.∠4 D.∠5【解析】因为∠1与∠5是直线AB、CD被第三条直线所截得到的同位角,由此得到答案.【解答】选D.【点评】本题考查了同位角、内错角与 Parallel lines and triangles are two important basic graphics in junior high school geometry, but also the common knowledge of the examination points, as the background of the questions everywhere, is now part of the examination questions for students to learn for reference. As shown in Figure 1, AB∥CD is known, and the angle of the same phase with ∠1 is () .A.∠2 B.∠3C.∠4 D.∠5 [Analysis] Because ∠1 and ∠5 are straight lines AB, CD is the third line obtained by the interception of the same-bit angle, which got the answer. 【Answer】 choose D. 【Comments】 This question examines the same bit angle,