Answer
$DF = 5\sqrt 3 \approx 8.66$
$FE= 10$
Work Step by Step
By the given Figure
$\angle D=90^{\circ}$ given
$\angle E=60^{\circ}$ given
So remaining$ \angle F=30^{\circ}$
now $DE= 5 $ given
By Theorem 5.5.2/ (30-60-90 Theorem)
$DF = 5\sqrt 3 \approx 8.66$
$FE= 10$
