Do I have to convert the Outlines to Objects?

Hello

I recreated an Ambihelical Hexnut ( http://mathworld.wolfram.com/images/eps-gif/AmbihelicalHexnut_600.gif ),
a Penrose Staircase ( http://mathworld.wolfram.com/images/eps-gif/PenroseStairway_700.gif ),
and a Penrose Triangle ( http://mathworld.wolfram.com/images/eps-gif/PenroseTriangle_500.gif ).

 Is it possible to connect the 3 lines in the corners, ie joining 3 nodes into a 1 node corner with 3 lines, without converting the Outlines to Objects?

Thanks!
Mulberi