Answer:
arccos(439/1976)
Step-by-step explanation:
The largest angle is opposite the longest side. So, by the Law of Cosines, if we let this angle be x,
[tex]x=\arccos \left(\frac{7.6^2 + 5.2^2 - 8.2^2}{2(7.6)(5.2)} \right) \\ \\ =\arccos(439/1976)[/tex]
