Perpendiculars from a point on the line between the endpoints of the angle bisectors

Let ABC be a triangle. Let AA' and BB' bisect the angles CAB and ABC. Let P be a point on A'B' and PQ be perpendicular to AB. Let PB'' and PA'' be perpendicular to AC and BC. Then PQ = PA'' + PB''Componente Curricular::Ensino Médio::Matemátic