The students discuss how to find the angle labeled

$.$

Student $1$: I think we can use cosine equals $5\mathrm{.}7$ over $6\mathrm{.}2.$

Student $2$: We could use Pythagoras to find the side $\text{'}$n$\text{'},$ then use cosine equals $\text{'}$n$\text{'}-$ whatever it turns out to be $-$ over $6\mathrm{.}2.$

Which student do you think is correct?