In the rectangular coordinate system, the coordinates of the three vertices of △ ABC are a (1,1), B (3,1), C (1,3), respectively. This paper explores the three vertices of △ def symmetrical about the origin of △ ABC Point coordinates, and determine the analytical formula of line EF

In the rectangular coordinate system, the coordinates of the three vertices of △ ABC are a (1,1), B (3,1), C (1,3), respectively. This paper explores the three vertices of △ def symmetrical about the origin of △ ABC Point coordinates, and determine the analytical formula of line EF

D(-1,-1),E(-3,-1),F(-1,-3)