i got one of those ruby's triangles, and after a few hours of playing with it, one of the tips broke off, or came apart i should say

it just needs to be glued back together, what type of glue would work on this plastic?

i've never had much luck with super glue/crazy glue on my rubik's revenge way back when, it always came apart again

Contact cement is probably going to create a much stronger bond than Super Glue. I started making my Extended Cuboctahedron with Super Glue, but all (ALL!) of the extensions kept breaking off. I switched to Contact Cement, and haven't had another piece break off yet.

That said, I've used Super Glue on Ruby's Triangle tips with success. I disassemble the puzzle, use what is probably too much glue, and let it sit for a few hours before reassembling. I've also stuck one or two on while the puzzle is still assembled, but be careful not to use too much, of course.

Sandy