Final answer:
Two vertices connected by an undirected edge are said to be 'adjacent to' each other. This term is used in the field of graph theory within mathematics to describe the direct connection between vertices in a graph. The adjacency of vertices is a fundamental aspect in the study of graphs and their properties.
Step-by-step explanation:
Two vertices that are joined by an undirected edge are said to be adjacent to each other. In graph theory, which is a part of mathematics, an undirected edge indicates a mutual connection between vertices, meaning there is no direction associated with the edge. The concept of adjacency is fundamental in the study of graphs, as it helps in understanding the structure and properties of various graph types, such as connected graphs, trees, and networks.
When it comes to answering the question of what it means for two languages to be related, the correct answer is that they evolved from the same older language. This means that over time, as languages develop and split into different dialects, some may evolve into separate but related languages due to their common origin.