What does "vertices" mean in math?

In geometry, a vertex is defined as a point where two or more lines meet. A triangle has three vertices. A parallelogram has four vertices. A six-sided figure has six vertices. A pentagon is a five-sided figure and has five vertices.

A vertex can also be defined as a corner of a three-dimensional figure. Cubes, cuboids and cones are all three-dimensional figures. A cube and a cuboid have eight vertices. The corners of a table meet in a vertex. A page of a book has four vertices. An angle has a vertex too. The vertex of an angle is the point where the two arms of the angle meet.