It depends on the shape of the sliced object. If the sliced object is a rectangular prism, the two-dimensional shape created by the slice would be a rectangle. If the sliced object is a triangular prism, the two-dimensional shape created by the slice would be a triangle. If the sliced object is a hexagonal prism, the two-dimensional shape created by the slice would be a hexagon. If the sliced object is a cube or a general parallelepiped, the two-dimensional shape created by the slice would be a parallelogram.
