在一个名叫几何的王国里,有一座繁荣的小城—凸多边形城,这里住着各种各样的多边形.城中有一个四边形家族,成员非常多,如不规则的四边形一家,平行四边形一家,梯形一家等等.其中平行四边形一家地位特殊,因为这个凸多边形城市的市长便是那大名鼎鼎、无人不晓的平行四边形.平行四边形处事公平,执政已有多年,在它的带领下,凸多边形城市才发展成为一片欣欣向荣的景象.平日里,平行四边形市长最喜 In a kingdom called Geometry, there is a small, prosperous town - a city of convex polygons, where all kinds of polygons live. There is a quadrilateral family in the city with many members, such as the irregular quadrilateral and the parallelogram. The trapezoids and so on. Among them, the parallelogram has a special status, because the mayor of the convex polygon city is the famous parallel quadrilateral that nobody knows. The parallelogram is fair and has been in power for many years. Under its leadership, it is convex. Polygonal cities have developed into a thriving scene. On weekdays, the mayor of parallelograms