problema 16. __100 puncte__

[tex]\it AB'=AP+PB'\ \ \ \ \ \ (1)\\ \\ B'\ -\ simetricul\ lui\ B\ fa\c{\it t}\brevea\ de\ d \Rightarrow d\ -\ mediatoarea\ lui\ [BB'] \Rightarrow\\ \\ \Rightarrow PB'=PB\ \ \ \ \ \ (2)\\ \\ (1), (2) \Rightarrow AB'=AP+PB[/tex]