Lorenz, Every single line through a point within an angle will meet at least one side of the angle.

I know I have to Show that the parallel postulate 5 implies lorenz, and then lorenz implies parallel postulate 5.

Assume postulate 5 . So we are given AB and a point C not on AB. Choose B on AB draw CD to construct angle ECD= angle BDC.

I just don't get what Lorenz postulate means. Thats where I am getting stuck.

I know I have to Show that the parallel postulate 5 implies lorenz, and then lorenz implies parallel postulate 5.

Assume postulate 5 . So we are given AB and a point C not on AB. Choose B on AB draw CD to construct angle ECD= angle BDC.

I just don't get what Lorenz postulate means. Thats where I am getting stuck.