That is the Vertex
You have to count the lines on a solid figure
A vertex is the point where three or more edges of a solid figure meet.
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.
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
hexahedron
Cube
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. :)
A tetrahedron is a solid figure with 6 edges. There's no such thing as solid edges. A tetrahedron is a triangular pyramid, with 4 vertices, 6 edges and 4 triangular faces. In a regular tetrahedron (the first Platonic solid) all triangles are equilateral.