ok so first when u look at this kinda question, you see that it's a 30-60-90 triangle. that means it follows that angle rule.
so you can search up the rule for reference, but it's basically
30º -> x
60º -> x√3
90º -> 2x
alright and now you know that the leg opposite from the 30º is 7. That means that the leg opposite from the 60º will be (x)√3
now use substitution for x=7, and you'll get that
b = 7√3
