hi!! im in 8th grade and our band director made us learn to double tongue. now im just curious on how to triple tongue??? anyone know how???

very much the same.
instead of "tu ku tu ku tu ku"
You can learn the three variations"
1 "tu ku tu, tu ku tu, tu ku tu"
2 "ku tu ku, ku tu ku, ku tu ku"
3 "tu ku tu, ku tu ku, tu ku tu, ku tu ku"

The way i learned it, was:

TUh, KUH, Tee.

and backwards,
tee, kuh, tuh.

alternating these 2 helped me get better at triple tonguing faster.

but everyone is different, hope this helps :D

tu tu ku, ta ta ka, or to to ku, depending on the range you are playing in. Do what's comfortable, but start slow, practice cleanly then increase your speed as you go.

For real hard-core practice do some k-tongue exercises like, ka ka ka - ka ka ka - ka ka ka.

This will help develop ka tongue which will eventually improve your triple-tongue speed.
Also, make sure to keep your air flowing and think of your tongue as just a way of interrupting that air supply. Don't close off your air to make the sound.

http://trumpetsearch.com/how-to-play-trumpet