Answer: B
Explanation:
We would apply the law of Cosines which is expressed as
a² = b² + c² - 2abCosA
Where a,b and c are the length of each side of the triangle and A is the angle corresponding to a.
62² = 78² + 44² - 2(78 × 44)Cosx
3844 = 6084 + 1936 - 2(3432)Cosx
3844 = 8020 - 6864Cosx
6864Cosx = 8020 - 3844
6864Cosx = 4176
Cosx = 4176/6864
Cosx = 0.608
x = Cos^(- 1)0.608
x = 52.5° to the nearest tenth