2010-2011 Mock USAJMO Problems/Solutions/Problem 1
Problem
Given two fixed, distinct points and on plane , find the locus of all points belonging to such that the quadrilateral formed by point , the midpoint of , the centroid of , and the midpoint of (in that order) can be inscribed in a circle.
Solution
Coordinate bash with the origin as the midpoint of BC using Power of a Point.