[CM] sin(pi/11)

[Bill Schottstaedt]

I added sin-m*pi/n to the end of Snd's numerics.scm -- it returns
(as an expression suitable for eval) the exact value of (sin (* m (/ pi n)))
where n is made up of any number of factors of 2, 3, 5, 7, 13, 17, and
257, but there's one more possible case: 11.  I can't find an expansion
for it on the web, and my math type friends seem to be off carousing
somewhere.  And I skipped the class where they explained how to 
solve a quintic.  So, does any cmdisterian have access to Mathematica?
I need something like

FunctionExpand[Sin[Pi/11]]

or possibly TrigExpand -- if that doesn't work, I can dig around and
find the right command.  Thanks!!