make ur triangle and circle objects, ie either textures on flat planes or simple geometry. next look at
http://caad.arch.ethz.ch/info/maya/manual/...ipFXV2.fm2.html
which explains the flow along curve effect, as you want a path for your triangles and squares to follow. you want to instance your square to the emitter, then duplicate the whole thing for your circle.
hope this is what you're after
sam