Composition - rotation - cut

The assignment was to create a rotary shape from plaster with a metal template using the dialing technique. I spun a small cone, which I used as a core. Then I turned it upside down and made a larger cone around it. After the plaster dried, I cut the cone horizontally at the point where the small cone (core) ended and then removed it. A negative space was created in the cone - an inverted cone in a cone.