A cone would fit the given description
its a lens...1 curved edge = a circle, 1 flat surface = back, 1 curved surface = front. (these are used in some battery-less flashlights, as an example.)
Cylinder
Cylinder
hemisphere
The reflecting surface of a mirror is flat.
A cuboid has 6 flat faces but no curved surfaces. ..________ ./............../| /_______/.| |..............|.| |..............|./ |_______|/
Flat!
i think its curved
curved
A plane horizontal surface with no depth refers to a flat area on a curved surface.
A sphere sliced by a plane; or a cone.
A shape with 1 vertex, 1 edge, 1 flat face, and 1 curved face is a cone. The vertex is the tip of the cone, the edge is the circular base where the flat face meets the curved surface, and the flat face is the circular base itself. The curved face extends from the base to the vertex.