One of the important principles to understand in all animation, both traditional 2D and computer generated 3D, is that of the arc. Most natural movement, human and animal, takes place on an arc. From the flick of a finger, to the swing of a baseball bat or a moving tail, the majority natural movement occurs on wavelike arcs or in figure eight like movements. This lesson will introduce students to the principle through visual examples to study, as well as through some simple drawing exercises that can be completed over the course of several periods or as homework. Understanding the importance of arcs in movement will help animators create more fluid and natural movements, from the smallest to the broadest of actions.