Owner`s manual

182 MaxMotion for Machines
Scale Shapes (Ctrl+L)
The scale dialog box allows many options for resizing the files.
If you know that the job must be a certain width, type the dimensions
into the width dimensions box, and the height will be automatically
adjusted to preserve the original proportions of the job.
Similarly, if you know that the job must be a certain height, type the
dimensions into the height dimensions box, and the width will be
automatically adjusted to preserve the original proportions of the job.