No, vertices do not have to be pointed out. Vertices are the points where the edges of a shape or object meet. They can be sharp or rounded, depending on the shape or object.
A sphere.
No. An example of a 3D object without vertices is a sphere.
The easiest way to think of vertices on a 3-dimensional object is to think of vertices as corners. Now, which 3-dimensional object has 8 corners? That would be a trapezoidal prism.
Vertices imply a 3D object. Circles are 2D so do not have one, but if you meant a sphere, your answer would still be no. This is because you need a corner with three edges meeting together to form a vertex.
A vertice is a point where two or more lines connect. If an object is a closed object, meaning that all the line's endpoints are connected to another line's endpoint without any openings, then the object has as many vertices as it does lines. A square has four lines so it has four places where lines meet, called vertices. So a square has four vertices.
Cylinders have no vertices since the entire object is rounded. Only objects in which two lines meet in the same planar are are considered to have vertices.
It is the sum of the y-coordinates of the vertices divided by the number of vertices.
A tetrahedron.
As a 2d object, a diamond had four sides. As a 3d object, there are many different types of diamonds, all with their own numbers of vertices, edges and faces.
Vertices are corners. Thus, there are 4 corners in a square.
A rectangular prism is a three dimensional object which has two bases, both rectangles. It has six faces, twelve edges, and eight vertices.