Answer:
11.3
Explanation:
first we find angle F.
remember, all angles in a triangle always sum up to 180 degrees.
so,
F = 180 - 90 - 61 = 29 degrees
now we use the law of sines.
EF/sin(D) = ED/sin(F) = DF/sin(E)
DF = x
sin(E) = sin(90) = 1
5.5/sin(29) = x/1 = x
x = 11.3