学习“三线八角”时,有的同学常常会因三线八角的图形稍微复杂一点就分辨不清哪两个角是同位角,哪两个角是内错角,哪两个角是同旁内角.然而,同位角、内错角、同旁内角的判定恰恰是学习平行线的性质与判定的关键.其实,我们只要抓住三线中的主线——截线,就能正确判定某两个角是同位角、还是内错 When studying “three lines and eight horns,” some classmates often can’t tell clearly which two angles are the isoscender angles because the three-line octagonal pattern is a bit more complicated. Which two horns are the inner lopsided corners and which two horns are the same internal horns. However, the determination of the azimuth angle, the inner angle error, and the same side angle is precisely the key to learning the nature of the parallel lines and the decision. In fact, we can correctly determine whether two corners are the same by simply grasping the main line in the three lines—the cut line. Is there an azimuth or an internal error?