It depends on the angle of the plane of the cross section.
If it is parallel to the cube's face (or equivalently, two adjacent edges) the cross section will be a square congruent to the face. If the plane is parallel to just one edge (and so angled to a face), the cross section will be a rectangle which will have a constant width. Its length will increase, remain at a maximum level and then decrease. If neither, it will be a hexagon-triangle-hexagon-triangle-hexagon (triangles when passing through a vertex).
Yes, but not a regular one.
Along any edge
length = volume/cross-section
The vertical cross section of a right vertical cone is a triangle if that cross section is taken from the vertex. Any other vertical cross section will reveal a hyperbola (with endpoints on the base of the cone). A link can be found below.
You cannot have a 2d cylinder. The 2d cross section will depend on the plane of the cross section.
No, a cube cannot have an octagonal cross-section.
The cross-section of a cube can vary depending on how it is cut. If sliced parallel to one of its faces, the cross-section will be a square. If cut diagonally, the cross-section can be a rectangle or a more complex polygon, depending on the angle and position of the cut.
A square.
A square
Yes it can.
Infinitely many.
Rectangle
A cross section of a cube is formed by slicing through it in various ways. Shapes that cannot be a cross section of a cube include those with curved edges, such as circles or ellipses, as well as shapes with more than six sides, like an octagon. Additionally, any shape that cannot be formed by connecting straight lines or does not lie flat, such as a 3D object, would also not be a valid cross section of a cube.
Yes, but not a regular one.
It will be the same shape as a square
The following are some shapes having a square cross section: a cube, a cuboid, a square pyramid.
Cube, Cuboid. Any prism with a quadrilateral cross section