Triangle Choke
From FightWiki
http://www.youtube.com/watch?v=bt2sZFj9lLM
To begin, you must try to control both of your opponents wrist and creep your legs up a little higher in the guard. Push one arm up and slide the leg through and try to place that legs calf on the back of your opponents neck. Once locked push his arm that is stuck between your legs over to the opposiste side. Now you have a squeeze from your thigh and their own arm choking his neck. To make him tap grab the back of the head and pull down while slightly lifting your pelvis up.
- to prevent triangle chokes, once you recognize it, sit up as fast as you can. Try to push their legs forward and push out, While pushing them to the side, then take side guard. Or push your body up and the choke. Make sure they do not get it all the way and keep pushing forward, their legs will get hooked on the shoulder and make it difficult to choke. I do not perfer this method though. Fedor vs. Antonio Noguera is a good fight to view escapes from triangle chokes.

