notes an alternative could be as given in figure figure strongly connected graph there may exist more alternate structures make at least one more alternate structure for the same diagraph you must have observed that there is no limitation of number of edges incident on one vertex it could be noneoneor more the number of edges incident on vertex determines its degree in digraph we attach an indegree and an outdegree to each of the vertice in figure the indegree of vertex is and outdegree is indegree of vertex is the number of edges for which vertex is head and outdegree is the number of edges for which vertex is tail figure tree let us define special type of graph called tree graph is tree if it has two propertiesit is connectedand there are no cycles in the graph lovely professional university