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 ...

3D mammograms can find more cancers than 2D mammograms alone. 3D mammograms are better at finding tumors in dense breast tissue. Combining 3D and 2D mammograms gives a higher radiation dose. There are ...