Calculating the resultant of two forces and angle? A force of $256 N$ and a vertical load of $537 N$. Trying to work out the resultant of the two forces and the angle at which it acts to the horizontal?

HINT:

The resultant ($R$) of any two forces say $P$ & $Q$ having angle $\alpha$ between them is given as $$R=\sqrt{P^2+Q^2+2PQ\cos \alpha}$$

The acute angle $\theta$ between the resultant & the force $P$ is given as $$\theta=\tan^{-1}\left|\frac{Q\sin \alpha}{P+Q\cos \alpha}\right|$$