Let D be the point on the side BC of the triangle ABC such that AD is the bisector of ∠CAB. Let I be the incenter ofABC.(a) Construct the points P and Q on the sides AB and AC, respectively, such that PQ is parallel to BC and the perimeter of the triangle APQ is equal to k⋅BC, where k is a given rational number.(b) Let R be the intersection point of PQ and AD. For what value of k does the equality AR=RI hold?(c) In which case do the equalities AR=RI=ID hold? geometryincenterperimetergeometry unsolved