[MiKTeX] Sans-serif math?

[Rutten, M. <Mar...@ds...>]

Is it possible to make the default math font sans-serif?  My intended use is
for slides with equations in them (I'm using a modified Prosper template).
Also, using \mathsf on greek symbols has no effect.  Is there a readily
available (free) sans-serif font containing the greek symbols?

Sorry, this this isn't a specific MiKTeX question, but a reasonably thorough
web search didn't result in any answers.