MathDB
Length of RS is independent on P

Source: Baltic Way 2011

November 6, 2011
geometrygeometric transformationrotationgeometry proposed

Problem Statement

Let ABAB and CDCD be two diameters of the circle CC. For an arbitrary point PP on CC, let RR and SS be the feet of the perpendiculars from PP to ABAB and CDCD, respectively. Show that the length of RSRS is independent of the choice of PP.