Yes
The cross section can be a triangle, rectangle or a hexagon.
rectangle
rectangle
It is a rectangle.
It is a rectangle.
It is a rectangle.
A cube cannot be a rectangular prism, as the cross section of this prism would be a rectangle, as opposed to a square. A square prism (if that is what it is called) could be a cube, but is not necessarily.
The answer depends on the inclination of the intersecting plane. The cross section can be a point, a triangle, a rectangle, a pentagon or a hexagon.
A cylinder has a circular cross section, a rectangular prism has a rectangular cross section.
A rectangular prism has a rectangular cross section whereas a cylinder has a circular cross section
A triangular prism has a triangular cross-section. A rectangular prism has a rectangular cross-section.
The cross-section cut parallel to the base of a right rectangular prism will also be a rectangle. This is because the sides of the prism maintain their rectangular shape throughout, regardless of where the cut is made, as long as it is parallel to the base. The dimensions of the cross-section will depend on the height at which the cut is made but will always retain the rectangular form.