Triangle Choke Defense

There are three street-fighting ways to defend against this technique when your caught in it and the first is to bite the thigh because your head will be stuck between his legs.  The second defense is punches to the groin a lot of people when caught in it get their head and one arm stuck but you still have one free hand.  The third is to throw some hard knees and combine them with hard punches.  The greatest defense, i learned from Bruce Lee is to be aware to avoid being harmed in the first place.

Standing rear choke defense

If your caught in a standing rear-choke the best thing you can do is use your hands to try an stop it by reaching for the hand that's on the back of your head and try to pull it loose.  While doing this your free to kick backwards to the lower parts of the legs if that fails start attacking the nuts with punches.  The other things are headbutting backwards before it gets too tight and elbowing to the stomach.

Ground Headlock Defense

If someone ever gets you in a headlock on the ground and your on top you can knee to the groin or if you have your hands free and you can reach your attackers head start punching or try to grab the neck.  If your on the bottom the only thing, i can think of is trying to bite the arm or try to reach the groin area to crush something.