don't no
sphere
no shape
a face
The shape that has one side of a face is a "cone." A cone has a circular base and a pointed top, resulting in one curved surface and one flat face. It can be visualized as a three-dimensional object that tapers smoothly from the base to the apex.
Possibly a face - or an edge. It would help if the question was properly phrased.
sphere
no shape
A sphere
A blob.
a line
A Moebus strip.
It is a face.
Circle. Sphere.
Mobius strip
An edge.
a face
To answer this question more details need to be provided. For example one a 3D shape one side is called a face.