This brochure was designed to be a two-sided brochure that could be tri-folded. The first page has all of the text in the right column so it would be seen on top when tri-folded. On the second page, the pictures and author info are in each of the three columns created by tri-folding. The only thing not included in this design that you will sometimes see on a brochure is a blank column that is used for mailing information and postage.
Standard tri-fold brochures are frequently printed two-sided on an 8.5" x 11" page in landscape orientation. Once you set your printer to print this brochure on one two-sided page rather than two separate pages, you should be able to tri-fold it.
Hope this answers your question.
That clarifies everything.