Using Pythagoras theorem where
Hyp^2=Opp^2+Adj^2.
Where
Hyp=7
Opp=x
Adj=√14
7^2=x^2+(√14)^2
Make x^2 subject of formula
x^2=7^2-(√14)^2
x^2=49-14
x^2=35
Find square root of both sides
x=√35
this implies that
SinK=Opp/Hyp
Sin K=√35/7
Sin K=0.84515
Approximately
Sin K=0.85
