Given four points A1,A2,A3,A4 in the plane in such a way that A4 is the centroid of the △A1A2A3,
find a point A5 in the plane that maximizes the ratio max1≤i<j<k≤5T(AiAjAk)min1≤i<j<k≤5T(AiAjAk). (T(ABC) denotes the area of the triangle △ABC. )
J. Suranyi