Hello, I'm trying to solve this problem, I really didn't know if it was Algebra or Trigonometry, so if this is the wrong section, I'm sorry.

On the next figure, the segments m1 and m2 are parallel, what's the value of X?

I tried solving using a system of ecuations, but I can't cause I have 3 unknowns, m1, m2 and x. Tried lots of things but couldn't solve it.

Thanks in advance.