the zagreb indices of line graphs of some product graphs

A graph is a mathematical model used to predict the topology of a given system.in chemical graph theory, a graph is designed by considering atoms as vertices and edges asbonds between atoms of a particular molecule. a topological index is a numeric quantity from the structure of a graph which is invariant under auto morphisms of the graph under consideration. in this paper, we computed the zagreb indices of line graphs of some graphs and the product graphs pn × pm and pn × cm.