Does this question involve sin, cos..?
If yes,
sin 60= x/12
x= 12sin 60
x=10.392(5s.f)
x=10.4(3 s.f)
Using pythagoras theorem,
a^2 + b^2 =c^2
x^2 + y^2= 12^2
(10.392)^2 + y^2 = 144
y^2=36.006
y=
y=6.0005
y=6.00(3 s.f)
For significant figures and decimal place, you should do what your school requires whether its 3 s.f or 2 d.p. I hope this helps..