The height and width of slides

The dimensions of the slides are set by the lengths
\begin{MD}
\slidewidth\\
\slideheight
\end{MD}
The ``width'' refers to the width of a slide when looking at it in landscape orientation, whether it is a landscape or portrait slide (and the same goes for ``height''). The default width is 8.5 inches and the default height is 6.3 inches. The slide environments have an optional argument that lets you change the dimensions of a single slide, as in
  \begin{slide*}[7.5in,6in]
The first dimension is the slide's ``width'', and the second dimension is the slides ``height''. If you remember what we said about what ``width'' and ``height'' mean, you will see that the above example begins a portrait slide that is 7.5 inches high and 6 inches wide.