Students will investigate 3D visualizations of volumes created by rotating a function about the x-or y-axis. They will understand the concept and reason for the volume formula in order to be prepared for generalizations. Students will solve the definite integral by hand using the fundamental theorem of calculus and using the definite integral capabilities of the TI-Nspire. They will compare their solution with the volume of a cone that would be the same as or approximate the shape.