# Duotransitionalterprism

A **duotransitionalterprism** is an isogonal polytope formed from the convex hull of two orthogonal duoprisms where one base is a truncated version of the other, in such a way that the prisms of the smaller base have the same radius of the larger base. They are closely related to the duoexpandoprisms and duotruncatoalterprisms, and are transitional cases in between these two families. The simplest possible duotransitionalterprism is the tesseract, while the simplest non-trivial duotransitionalterprism is the triangular duotransitionalterprism, which is the convex hull of two orthogonal triangular-hexagonal duoprisms. The dual of a duotransitionalterprism is a duotransitionaltertegum.

The 4D duotransitionalterprisms have one ring of 2N n-gonal trapezorhombihedra, which are polyhedra with 2 n-gonal bases linked by squares and trapezoids. They are connected by a layer of rectangular trapezoprisms to another ring of n-gonal prisms. Their vertex figures are isosceles trapezoidal pyramids.