a circle has no face
a sphere on the other hand does
The answer is - a cone.
a cylinder
A "hemisphere" - a ball that's been cut into 2 equal parts. i.e "half a sphere".
flat
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.
A cone. It has a circle for the base, and a curved face tapering to a point.
The answer is - a cone.
Semi Circle
2D = semi circle 3D = hemisphere
cylinder circle
It could be a semi-sphere but mostly it's a cone.
a cone
a cylinder
A "hemisphere" - a ball that's been cut into 2 equal parts. i.e "half a sphere".
flat
There cannot be such a shape. It is not a cylinder because a cylinder sdoes not have a rectangular face. A rectangle must be a flat face and the only flat faces in a cylinder are the circle faces. The curved face can be "opened out" into a rectangular shape but because the face is curved it cannot be rectangular.
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.