A sphere.
No. Congruent means the same shape and the same size. Two perfect circles would be the same shape but they might not be the same size.
A shape that has all sides connected. Examples are squares, circles, ovals, octagons, etc.
The shape of a circle is round. Circles are plane shapes that have all points that are the same distance from the center.
Not too sure of your question but maybe it's a sphere that looks like a circle from different views
All circles are similar, they all are the same shape, regardless of size. Only if they have equal diameters, would they be congruent.