Definition:Prism/Base/Euclidean Variant

Definition

 * Prism-variant.png

Although the base of a prism is generally understood to be one of the opposite faces which defines the prism, was inconsistent in his usage in.

In his, he defines the base of one prism as being one of the opposite parallel faces, but of the other he defines the base as being an arbitrary one of the parallelograms.

Using this definition, the parallelogram $PQTS$ in the above diagram is the base of the prism $PQRSTU$.