How can the face of a rectangular pyramid determine the shape and dimensions of a slice of the pyramid

A rectangular pyramid is a pyramid which is formed whose base is a rectangle and rest four faces are triangles.

When we cut the rectangular pyramid into slices vertical across the vertex i.e. perpendicular to the base of the triangle then we will obtain the triangles which represent the face of the rectangular pyramid.When we cut the rectangular pyramid horizontal i.e. parallel to the base of the pyramid then we will obtain rectangles of different dimensions.Next when we cut the pyramid other than the above two ways then we will get a quadrilateral.