Vì N là trung điểm AB

Suy ra NA=NB=AB:2=8:2=4

1.....used to watch TV. 2......used go to a kindergarten. 3......used to cry a lot. 4......did you use to live. 5......used to want to be. 6.....used to be shy. 7......use to get up early. 8.....used to make a lot of spelling mistakes. 9.......use to drink coffee. 10.....you use to wear new clothes.