Hiya, I am trying to solve something but it's driving me mad, please save me, no this is not math homework I am 30 years old.

I have this triangle here:

Hypot = 60
Adjacent = 30
Opposite ??

lets give them nice names
Hypot = C
Adjacent = A
Opposite = B

I do not know the angles apart from that this is a right angle triangle.

What are the steps to solve this?

I am JavaScript centric so code in this language or explanations in code would be super! (math is not my strongest suit sometimes)