Final answer:
When a rectangular prism is sliced with a plane parallel to the base, the resulting cross section is a shape that is identical to the base of the prism.
Step-by-step explanation:
When a rectangular prism is sliced with a plane parallel to the base, the resulting cross section is a shape that is identical to the base of the prism. In other words, the two-dimensional shape that is sliced is the same as the base of the prism.