If x u v X then the line x is said to join of u and v The

Last updated: 9/13/2023

If x u v X then the line x is said to join of u and v The points u and v are said to adjacent if x u v We say that the points and the line x are incident with each other If two distinct lines x and y are incident with a common point then they are called adjacent lines A graph with p points and q lines is called a p q graph Note When there is no possibility of confusion we write V G V and X G X Examples Let V a b c d and X a b a c a d G V X is a 4 3 graph This graph can be represented by a diagram as shown in Fig 1 1 ob 1 Fig 1 1 In this graph the points a and b are adjacent whereas b and c are non adjacent