$\mathrm{A}(3,-4)$ is a vertex of $\triangle \mathrm{ABC}$ and $3 x+4 y-18=0$ is the perpendicular bisector…
$\mathrm{A}(3,-4)$ is a vertex of $\triangle \mathrm{ABC}$ and $3 x+4 y-18=0$ is the perpendicular bisector of the side $\mathrm{AB}$. If $\mathrm{C}=(6,3)$ then the centroid of the triangle is