Let $R = \left\{ {\left( {3,3} \right),\left( {5,5} \right),\left( {9,9} \right),\left( {12,12} \right),\left( {5,12} \right),\left( {3,9} \right),\left( {3,12} \right),\left( {3,5} \right)} \right\}$ be arelation on set

$A = \left\{ {3,5,9,12} \right\}$

Clearly, every element of $A$ is related to it self.

Therefore, it is a reflaxive.

Now, $R$ is not syminetry because $3$ is related to $5$ but $5$ is related to $3$.

Also $R$ is transitive relation because it satisfies the property that if $aRb$ and $bRc$ then $aRc$.