Styrofoam is a perfect starting point for many fun and beautiful projects. Use as a base for floral arrangements or craft centerpieces. Excellent for science projects, dioramas or holiday decorations. Measurements: 3 in. cone = 3" high x 2" base, 6 in. cone = 6" high x 3" base, 12 in. cone = 12" high x 4" base.