等腰三角形是一种特殊的三角形，它的重要性质具有很好的应用价值．等腰三角形两店用相等的性质是论证两角相等的常用依据之一，而等腰三角形的三条主要线段（顶角平分钱、底边上的中线和底边上的高）重合（简称“三线合一”）的性质是论证两条线段相等、两个用相等及两条直线 Isosceles triangle is a special kind of triangle, its important properties have a good application value. Isosceles triangle two stores use equal property is one of the common basis to prove the equality of the two corners, and the three main line segments of the isosceles triangle (vertical angle equalizes the money, the midline on the bottom edge and the height on the bottom edge) overlap (referred to as The “three-in-one” feature is the demonstration that two lines are equal, two are equal, and two lines are