Pages to pdf export results in a smaller page size, how can I make the page size as setup in Pages? I have a 48 by 36 inch poster in Pages. I can see size in Page Setup. The print people want the poster as a pdf so I export it to pdf.

When I open the pdf in Adobe, and look at Page Setup, it tells me that the page size is 8.5 by 11 inches.

I can't afford to make any mistakes in the printing. How can I make sure the pdf I send to the printer is the correct size?
Very easy answer to this. The size is under Properties in the File menu. There the page size is listed.