“三角形的中位线,平行于第三边并且等于第三边的一半”.是一个重要定理.有一个特点,在同一个题设下有两个结论:一个结论是表明两条线段的位置关系(平行),另一个结论是表明两条线段的数量关系(一半).在应用这 “The median line of the triangle, parallel to the third edge and equal to half of the third edge” is an important theorem. There is a characteristic that there are two conclusions in the same question: A conclusion is to indicate the position of two line segments. Relationship (parallel), another conclusion is to show the relationship between the number of two segments (half). Apply this