A face.
It is called the surface area.
It is a polyhedron.
Yes and its flat surface faces are in regular shapes.
They are the faces of the polyhedron.
It is a face of the polyhedron
They are its faces
A face.
It is called the surface area.
cross section
It is a polyhedron.
Yes and its flat surface faces are in regular shapes.
They are the faces of the polyhedron.
It is a definitional requirement. If any face is not flat, then it is not a polyhedron.
The face of a polyhedron is any of its flat surfaces
faces every polyhedron has one
Each face of a polyhedron must be a polygon: a flat surface bounded by straight lines. So, if any of the faces is curved, the shape is not a polyhedron.