For a better understanding of the question please check the attached diagram.
As can be clearly seen from the diagram, the point of intersection of the perpendicular bisectors of the sides of the triangle [tex] \Delta ABC [/tex] is the point P and we know that the center of the circumscribed circle of a triangle is the point of intersection of the perpendicular bisectors of its sides.
Thus, using these two pieces of information we can conclude that the Point P is the center of the circumscribed circle of [tex] \Delta ABC [/tex].
