平行六边形及其性质西安市西光中学刘康宁定义１三组对边两两平行的凸六边形叫做凸平行六边形．本文中不加说明的平行六边形都是凸的．定义２平行六边形间隔的三边所在直线围成的三角形叫做这个平行六边形的伴随三角形；以间隔的三个顶点为顶点的用形叫做这个平行六边形的... Parallel Hexagons and Their Properties Xi’an Xiguang Middle School Liu Kangning Definition 1 The three parallel convex hexagons on the opposite side are called convex parallelograms. The parallel hexagons not described in this paper are all convex. The triangle defined by the straight line of the three sides of the definition of two parallel hexagonal spacing is called the companion triangle of this parallel hexagon; the shape of the three vertices with intervals is called the parallel hexagon...