Beamer for letter size paper

Question

My daughter is in high school and is working on a science project. She has really enjoyed writing the paper in LaTeX. Now, she has to make a tri-fold presentation of the major points. In the past, that has meant powerpoint printed onto letter-size paper then pasting those pages (one slide per page) onto the board. How can we resize beamer to have at least the same aspect ratio as letter-size paper? Ideally, we would have the same dimensions, also, but that is not so important as we can scale at print time. I have used beamerpresentation in the past, but that generates just one page, I think. Any suggestions are appreciated. The default is to simply use beamer as-is and scale to as close to letter size as possible when printing.