设AB中点为D,AC中点为E向外延长BC,得B',C' (B'在BC左侧,C'在BC右侧),使B'B=CC'=BC/2则B'C'=2BC=32,AB'=2BE,AC'=2DC所以:AB'+AC'=2(BE+DC)=60设B',C'坐标为(-16,0),(16,0)A的轨迹方程为椭圆x^2/a^2+y^2/b^2=1c=16a=60...