如果a/b=c/d=…=m/n,(b+d+…+n≠0),那么(a+c+…+m)/(b+d+…+n)=a/b. 这是九年义务教材初中《几何》第二册第205页介绍的等比性质.这个性质在几何证明中应用广泛,但教材未作介绍,为了弥补这一不足,本文以教材中的部分习题为主,对此作了全 If a/b=c/d=...=m/n, (b+d+...+n≠0) then (a+c+...+m)/(b+d+...+n)=a/b. It is the equal-magnitude nature of the introduction of the nine-year compulsory textbook junior high school “Geometry” Volume II page 205. This property is widely used in geometrical proof, but the teaching material is not introduced, in order to make up for this deficiency, this article takes part of the exercises in the textbook as Lord, made a full