IMO 1972 LL USS43
A fixed point A inside a circle is given. Consider all chords
IMO 1972 LL USS43
Origin: USS
Problem
A fixed point A inside a circle is given. Consider all chords XY of the circle such that \angleXAY is a right angle, and for all such chords construct the point M symmetric to A with respect to XY . Find the locus of points M.