一、填空题
1.__________________________组成平面直角坐标系.
2.(1)图1中多边形ABCDEF各顶点坐标为
_____________________________________________________
(2)A与B和E与D的横坐标有什么关系____________________________________
(3)B与D、C与F坐标的特点是________________________________________________.
(4)线段AB与ED所在直线的位置关系是_________________________________________