To answer this question I am going to use a cylinder. A face or side would either be the top or bottom. It is a flat surface on the object.
a base.
face
Each side is called a face.
a face is 1 side of a geometric solid.
A parallelogram is a 4 sided geometric figure with opposite side parallel.
It is called the face
A closed geometric figure with four sides, each side being a straight line
It is called a face.
a face.
a face
Face.
A lot of people think that the face in geometry is the side of a three dimensional figure, but it can really mean the specific side of a 2-d figure as well. Face just means the front of a figure for the side you're looking at. You can have the face of a circle, for example. It just means the side of the circle you're referring to.