A cone, a section of a sphere.
This is because the material the ballon is made of is shaped differently. The ballon will stretch and try to achieve a perfect round shape, but can not due to limitations in the way the ballon is made. One can however buy balloons that are almost perfectly round when inflated.
A cone has one vertex and one edge.
triangle
You can take a round cup or glass and set it in the middle of the paper and then taking a pencil you can trace the outer edge of the cup. You should have a perfect round circle upon completion.
A cone has one vertex, one edge, and one base.
A simple machine is the wheel, build one by cutting a perfectly round shape and fixing a rod through its centre to act as an axle. The simplest machine is a lever.
The edge of a 3D shape is called an "edge." It is the line segment where two faces of the shape meet. In geometric terms, an edge is one of the fundamental components that define the structure of polyhedra and other solid figures.
A line?
A circle?
A cone.
The shape that has zero vertices and edges and one face is a sphere. A sphere is a perfectly round three-dimensional object where every point on its surface is equidistant from its center. Unlike polygons or polyhedra, it does not have corners or edges, making it unique in its geometry.
A loonie, which is the colloquial term for the Canadian one-dollar coin, is primarily a circular shape. It has a smooth, round edge and features a design on both sides. The coin's circular shape allows it to roll easily and fit into standard coin slots.