AВ=sqrt((x_(В)-x_(A))^2+(y_(В)-y_(A))^2+(z_(В)-z_(A))^2)=
=sqrt((0-(-3))^2+(-2-2)^2+(-1-4)^2)=sqrt(9+16+36)=sqrt(50)
AC=sqrt((x_(C)-x_(A))^2+(y_(C)-y_(A))^2+(z_(C)-z_(A))^2)=
=sqrt((1-(-3))^2+(5-2)^2+(9-4)^2)=sqrt(16+9+25)=sqrt(50)
АВ=АС=sqrt(50)
Треугольник АВС - равнобедренный.