It is the vertex and its plural is vertices
Triangle
a vertex
A sphere. In Geometry, it is a round solid figure. Every point on it's surface is an equal distant from it's center.
That is the Vertex
A star, cone, pyramid.
It is the point of a dihedral (solid) angle.
A Sphere.
A sphere is a solid figure in which every point is equidistant from a fixed point called the center.
circle
it is a triangular pyrimid
A sphere
A vertex is the point where three or more edges of a solid figure meet.