Step 1
Find DE
Applying Pythaorean Theorem
DE^2=EF^2+FD^2
substitute
DE^2=8^2+14^2
DE^2=260
DE=√260
simplify
DE=2√65 units
step 2
Find the measure of angle E
we have
tan(E)=14/8
m
step 3
Find the measure of angle D
Remember that
E+D=90 -----> by complmentary angles
so
mm