You are looking for the macros
graphicx packages (→
graphics manual, 3.3 “Scaling”, p. 3).
\scalebox macro expects ratios like those you’d use in
\includegraphics, you you would be using
or, if you rather want to resize the content to a fixed width (or height),
! means that the content gets resized so that it keeps its aspect ratio.
There exist also a starred version of
\resizebox and you can use the lengths
\depth to refer to the original sizes of the content; meaning the factor
.5 could be used with