19.如图,已知$△ ABC ≌ △ DEF$,点$B,E,C,F$在同一直线上.
(1)若$∠ A=95°$,$∠ F=55°$,求$∠ DEF$的度数.
(2)若$BC=6$,点$E$是$BC$的中点,求$CF$的长.

19.(1)$\because △ ABC≌△ DEF,∠ A=95°,∠ F=55°$,
$\therefore ∠ A=∠ D=95°$.
$\because ∠ D+∠ F+∠ DEF=180°$,
$\therefore ∠ DEF=180°-∠ D-∠ F=180°-95°-55°=30°$.
(2)$\because △ ABC≌△ DEF,BC=6$,
$\therefore BC=EF=6$.
$\because$点$E$是$BC$的中点,
$\therefore BE=CE=\frac{1}{2}BC=3$.
$\therefore CF=EF-CE=6-3=3$.