In the following image if force the triangle PAN was right angle at P then the component of force in the direction of displacement would be $F\sec\theta$ so work $F*Displacement(AC)*\sec \theta $.
I understand why it is $\cos \theta$ but why cant it be $\sec \theta$ also?
I would greatly appreciate a solution to this doubt 🙏.
(the question got removed cause the site thought im asking a hw question but im not)