The cross section of a pyramid shrinks from the shape of the base down to a point as you move along its axis from the base to the apex.
The cross section of a prism is constant along its axis.
A triangular prism has a uniformed cross-section whereas a rectangular pyramid does not.
A cylinder has a circular cross-section whereas a cuboid has a quadrilateral cross-section.
triangle
It'll help you divide the pyramid into sections that are easy for you to study from
square pyramid
A triangular prism has a uniformed cross-section whereas a rectangular pyramid does not.
difference between cross section and block daigram
I assume you mean between prism and pyramid. I suggest you look at some picture of prisms and pyramids, to get it perfectly clear. In any case, a prism has the same horizontal cross section from the bottom the top. On the other hand, the lines of a pyramid get together towards the top, to a point. If you take a horizontal cross section, at the base it will be larger, but the closer you get to the top, the smaller such a cross section will be.
A cylinder has a circular cross-section whereas a cuboid has a quadrilateral cross-section.
A cylinder has a circular cross section, a rectangular prism has a rectangular cross section.
A cylinder has a circular cross section, a square prism has a square cross section.
triangle
It depends on the pyramid. If it is a square based pyramid, a horizontal plane will give a square cross section, a plane inclined by a rotation parallel to one of the base axes will give a rectangular cross section whereas a plane inclined by rotation along both basal axes will result in a parallelogram cross section. Not sure how you get a parallelogram from a pentagonal or hexagonal (etc) pyramid.
triangle
A 2D representation of a square-based pyramid is called a square pyramid net or a square pyramid template.
The horizontal cross section of a rectangular pyramid is a rectangle.
a square