What is the cross section created when a vertical slice is made perpendicular to the 2 bases of a triangular prism?

A.

a triangle

B.

ellipse trapezoid

C.

a square

D.

a rectangle

This is always a rectangle, because it will have 2 sides parallel the bases, and the other 2 sides are perpendicular to any line in the plane of the bases (property of a prism) this makes them parallel as well, because they are perpendicular to parallel lines and makes the shape a rectangle.