That is the Vertex
A vertex is the point where three or more edges of a solid figure meet.
You have to count the lines on a solid figure
There is no solid figure with only four edges. The smallest solid figure is the tetrahedron, made up of four triangular faces, but it has six edges.
The point where three or more edges of a 3D figure meet is called a vertex. In geometric terms, a vertex is a fundamental component of polyhedra and other solid figures, serving as a corner or a junction point for the edges. Each vertex can be connected to other vertices by edges, forming the overall shape of the solid.
If you are a solid figure with no vertices or edges, then you are a Sphere.From the lighter side: And that means that we can no longer be friends...
sides of the solid figure
EDGES
Cube
hexahedron
CIRCLE
A hexagon is a six sided figure.
A vertex on a cube, for example, is where any three edges meet. On a pyramid (square type) it could be at the point on the top or the 4 bottom edges. :)