E -X -T -E -N - D your Knowledge:
Edge Coloring
So far we have been assigning colors to the vertices so that
no two vertices that are the same color are connected by an edge.
Edge coloring is the process of assigning colors to the edges
of a graph so that no two edges of the same color meet at the same
vertex. The smallest number of colors needed to color a graph is
called the edge chromatic number of the graph.
Find the edge chromatic number of the following graph:
