This document discusses three key elements of sculpture: shape, mass, and line. It defines shape as a 2D enclosed area, mass as the solid material contained within a sculpture's surface, and line as a continuous mark with length and direction. It then provides images and questions to analyze several classical sculptures including The Thinker, Flying Horse, Discobolus, and an unnamed figure, examining their shapes, masses, details, implied motions, and other artistic elements.