Question

The lengths of the sides of a triangle are 7.6 cm, 8.2cm , and 5.2cm . Find the measure of the largest angle.

Answer 1

arccos(439/1976)

Explanation:

The largest angle is opposite the longest side. So, by the Law of Cosines, if we let this angle be x,

`x=\arccos \left((7.6^2 + 5.2^2 - 8.2^2)/(2(7.6)(5.2)) \right) \\ \\ =\arccos(439/1976)`