# Overlapping Volcano Unfolding of a Prismoid

Overlapping Volcano Unfolding of a Prismoid

A prismoid is defined to be a skewed, truncated pyramid over a convex polygon. A volcano unfolding of a prismoid is made by cutting all side edges and all but one top edge and then flattening out the figure in the plane. This Demonstration shows volcano unfoldings of prismoids with a regular base.

In any volcano unfolding of a prismoid, no pair of side flaps overlap. So any volcano unfolding of a pyramid is free of overlaps.

But, this Demonstration shows that a prismoid has a volcano unfolding in which overlaps occur.

Even so, a prismoid always has a volcano unfolding in which no overlap occurs [1, pp. 321–323].