How to find the angle between F2 and the x axis?

[Godblessyou]

Homework Statement

Find the angle between the x-axis and the force F2, and the magnitude of the resultant force?

Homework Equations

The equation of the triangle:
a(squared) = b(squared) + c(squared) - 2bc cos A

The Attempt at a Solution

What I did was that I said that since the angle between the f1 and the negative x-axis is 70 degrees. Then the angle with the +y axis should be 20 degrees, and therefore if we make the whole two forces as a triangle and solve using the cosine rule, we should get the value of the resultant force, but after wasting countless amounts of paper, I still haven't got a solution? Any help will be greatly appreciated!

 

[danago]

Was there any other information that you have left out? The angle could be anything without extra information.

 

[Godblessyou]

Nope that is all the information given!