Three.
3
Three.
Tetrahedron 3 triangles meet at each vertex 4 Faces 4 Vertices 6 Edges Cube 3 squares meet at each vertex 6 Faces 8 Vertices 12 Edges Octahedron 4 triangles meet at each vertex 8 Faces 6 Vertices 12 Edges Dodecahedron 3 pentagons meet at each vertex 12 Faces 20 Vertices 30 Edges Icosahedron 5 triangles meet at each vertex 20 Faces 12 Vertices 30 Edges
Where edges come together is a vertex
It is at the vertex of which the plural is vertices
Any 3-dimensional object whose faces are not all congruent, or in which they do come together at each vertex i the same configuration.
Four, in order to form a tetrahedron; this is alos the simplest possible 3-dimensional object constructed of regular polygons.
It is a vertex. But you may be thinking of an apex.
First, consider that at each vertex (point) at least three faces must come together, for if only two came together they would collapse against one another and we would not get a solid. Second, observe that the sum of the interior angles of the faces meeting at each vertex must be less than 360°, for otherwise they would not all fit together.
10
It's the point where the two sides of the angle come together.(Or start out from.)
Pyramid