Hello,

You can apply the Parallelogram Law of Vector Addition to proceed towards solution for your query.

-------  The law states " if we place two vectors so they have the same initial point, and then complete the vectors into a parallelogram, then the sum of the vectors is the directed diagonal that starts at the same point as the vectors."

------- Suppose the Forces acting be F1 and F2, so going the initial statement -

Resultant, R= 10 = √( F1^ 2 + F2^ 2).    ---- (i)

Also from the next statement -

146 = √ ( F1^ 2 + F2^ 2 + 2 F1 F2 Cos 60) ------ (ii)

On Solving the two equations you will get solution to your query.

Thank you.