A a solid figure on a flat surface is a plane figure (I do believe)
the flat surfaces of a solid figure are the
One of the figure which has no flat surface is Sphere.
a closed, flat figure is a polygon. But it is only a polygon when it is not round.
Yes a 2 dimensional figure is normally flat.
The flat surface of a solid figure is called a face. For example, a rectangular prism has 6 flat surfaces and therefore 6 faces.
a 2d figure a square
Plane?
It is a plane figure.
A face is the flat surface on a solid figure. For example, a triangular prism has five flat surfaces and therefore five faces.
polygon
It is a face.