Setting up the triangle starts with taking same side grips. Next, push one of your opponents wrist to their hip and pulling the other one towards you. Jump your leg over the side that you pushed your opponents wrist to (this creates the space to allow you to do so). Immediately lock up the triangle and begin working to pull the head down to control your opponent, breaking the posture. Cut the angle by taking your far side leg on the hip to push yourself to a sharper angle (cutting the angle), re-lock the triangle, pull on the head and finish.
1) Triangle Setup
2) Triangle Finish