I need a "T" made out of two six inch 1/8" wall thickness pipes.

I need a way to mark a chalk line on each pipe so I can cut it with a torch
and then fit the two together and weld.

I did a layout like this in drafting class thirty years ago. Made each piece
out of paper. Cut them out and wrapped around the pipe to mark the lines. I
don't remember much else about it.

Anyone know how this is done?

Karl