关于三角形三边关系,课本上作了介绍,但对这个定理及推理的应用却介绍的较少,本文着重归纳一下这个定理及其推论的各种应用.一、已知三条线段,判断它们能否构成三角形例1 以长度为下列各组数的三条线段为边,可作出三角形的是( ). The trilateral relations of triangles are introduced in textbooks, but there are few introductions to the theorem and the application of reasoning. This paper focuses on summarizing the various applications of this theorem and its inferences. First, three line segments are known to determine whether they can Whether to form a triangle Example 1 Three lines with the length of the following groups are edges, and triangles can be made ().