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The University of Edinburgh: Discrete Mathematics Graphs
This article is an in-depth look at graphs. Topics covered are graph models, terminology, representations of graphs, graph isomorphism, connectivity, Euler and Hamiltonian Paths, and more. Examples and explanations are included.
Mathigon
Mathigon: Graphs and Networks: Parties and Dating
This lesson uses handshakes at a party to explain complete graphs, when every vertex is connected to every other vertex. It shows how a formula was created to calculate the number of edges.