Professor Lucas Lepri demonstrates setting up and finishing a triangle choke from the guard. The technique emphasizes maintaining loose hips for mobility and moving them side to side. After an attempted sweep is blocked, the foot that was trapping the opponent's leg is placed on their hip. The arms are pulled, and the hips are lifted, transitioning directly into the triangle choke. Key details for finishing include flexing the ankle, crossing the arm, adjusting position, and pulling the opponent's head down while squeezing the knees.