Faghat ghabl az khundanesh taghyire esmhaye zir ra anjam dahid:noghateye tamas az D be Z taghyir mikonad va S be P taghyir mikonad va P,Q be Y,X taghyir mikonad.baghiye naoghate ba haman esmhast.
Let be the touch points of the incircle (with center ) with
then by using similarities (or...