Newton's third law states that for every action there is an equal and opposite reaction.

The top picture shows the third law in action because when the guy with his legs on the guys knees pushes off he will push the other guy back and he will go back himself. in the picture beside demonstrates the third law of motion because when one ball hist the others it will transfer its energy through the other balls causing the one on the end to go up and then the cycle repeats. That is how this law is active in these pictures.