If $A = \{ 1,2,3\}$ and consider the relation
$R = \{ (1,1),(2,2),(3,3),(1,2),(2,3),(1,3)\}$
Then, $R$ is

It is given that,, $A = \{ 1,2,3\}$

and $R = \{ (1,1),(2,2),(3,3),(1,2),(2,3),(1,3)\}$

$(1,1),(2,2),(3,3) \in R$

Hence we can say that, $R$ is reflexive.

(1,2)$\in R$ but (2,1)$\notin R$

Hence we can say that, $R$ is not symmetric.

(1,2)$\in R$ and (2,3)$\in R$

$\Rightarrow$ $(1,3) \in R$

Hence we can say that, $R$ is transitive.