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A 3D shape with all straight edges and flat faces is a polyhedron. Other 3D shapes with least one curved surface are not polyhedra. A 3D shape with regular polygonal faces, meeting at equal angles, is ...
A prism has a constant cross-section throughout its length. When the cross-section is a triangle, the prism is called a triangular prism. When the cross-section is a hexagon, the prism is called a ...