Triangular
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).
Parallel
Both, a cylinder and a prism have two faces (bases) at either end. These are parallel and identical. A plane that is parallel to these bases will cut the cylinder (or prism) in identical cross sections.
false
A sphere is.
A square pyramid is.
That's a statement that can apply to any rectangular prism.
The bases of a prism or cylinder are congruent and parallel and they meet the lateral face (cynder) or faces (prism) at right angles. A cross section parallel to the longitudinal axis will, therefore, be a rectangle.
cone and prism
All cross sections of a square pyramid that are parallel to the base are squares
True
True
The answer depends on the angle at which the axis of the cone intersects the cross-sections.
Circle: If the knife is perpendicular to the axis of the cone.Ellipse: If the knife is between (perpendicular to the axis of the cone) and (parallel to the side of the cone).Parabola: If the knife is between (parallel to the side of the cone) and (parallel to the axis of the cone).Hyperbola: If the knife is parallel to the axis of the cone.Triangle: If the knife is perpendicular to the base of the cone.Point: If the knife is parallel to the base the cone and through the apex
Every solid. All you need is the intersection with a plane parallel to the base.
because the cylinder has a circular base and a triangular prism has a triangular base so they are both basic shapes.