三角形、梯形中位线定义和中位线定理是平面几何的重要内容,是学习后面的课程的必备知识,是解三角形和梯形问题的重要工具郾这两个定理有一个共同的特点,在同一个题设下,有两个结论,一个结论是表明位置关系的,另一个结论是表明数量关系的郾在应用时,不一定同时需要两个结论,有? Triangle, trapezoidal median line definition and median bitline theorem are important contents of plane geometry, are necessary knowledge for learning the following courses, and are important tools for solving triangle and trapezoidal problems. These two theorems have a common feature in Under the same question, there are two conclusions. One conclusion is to show the positional relationship, and the other is to show that the application of quantitative relations does not necessarily require two conclusions at the same time.