It is the set of points, in 3-dimensional space, defined by the intersection of two planes which define faces of the shape.
cylinder
Spheres
sphere
There are lots of shapes: a sphere, an ellipsoid, a smoothed blob.
They are points where three or more edges meet.
3D shapes have edges, sides, and intersecting points
Cylinder
There are infinitely many shapes that do.
cylinder
Spheres
sphere
Cubes, cuboids, Trapezoid prisms, octahedrons
A cube has 6 faces
There are lots of shapes: a sphere, an ellipsoid, a smoothed blob.
cubes and rectangular prisms
They are points where three or more edges meet.
It means that the shape or a given figure has three or more edges meeting