“垂径定理及其推论”的教改建议○毛仕理（四川省乐至县石湍中学）初中几何第三册第七章第三节：“垂直于弦的直径”。教材是这样处理的，首先给出垂经定理：“垂直于弦的直径平分弦，并且平分弦所对的两条弧。”然后给出推论１，推论１包含三条结论。上述表述方式，本人... Suggestions for the Teaching of “Vertical Path Theorem and Its Inference” ○ Mao Shili (Shiqi Middle School, Lezhi County, Sichuan Province) Junior High School Geometry Volume 3 Chapter 7 Section 3: “Vertical to the diameter of the string”. The textbook is dealt with in this way. First of all, give the drape theorem: “Horizontal to the diameter of the string divides the chord, and divides the two arcs against the chord.” Then we draw corollary 1 and corollary 1 contains three conclusions. The above statement, I ...