i Know this may be easy for most of you but i am still learning.

y = x - w.
Look up law of cosines

>>8466908
will do.

Alright. So I have a ok understanding of law of cosines now can you explain to me how you got y=x-w.

>>8467006
Graphical vector addition
I can elaborate if you want me to

But OP the equation you need is already on the paper.. y^2 = x^2 + w^2 - 2cos theta x w, just sqrt that shit and plug numbers

>>8467068
Yes please

>>8467068
I would but I don't have any numbers to plug. That's the problem I was given from a coworker who used to teach physics in Russia.

>>8467094

He means how to derive the law of cosines.

Extend w and drop a perpendicular from the top vertex to the extended line. Now use the pythagoras theorem to find y

>>8467068
>>8467407

don't listen to this idiot, those aren't vectors.

can you redraw this same problem with vectors and get the right answer? yes, but it's only a useful way to do it if you're given the vector components - which you're not. Can you use the lengths and the angle to find the components, do vector addition, and use the components of y to find the length of y? of course you can, and it's easy. But with the information you're given it's easier and more direct to simply use the formula you have written down.
I use vectors for, i don't know, everything? But in this case it's just a useless abstraction because YOU HAVE THE FORMULA ALREADY.