Answer:
x = 46.37 degrees
Explanation:
Using cosine rule

Where a = 5 , b = 6.9 , c = 5 and C = x (Unknown)
In the cosine rule, a and b are the sides containing the angle and c is the opposite side of the angle C
Plugging in the values:

=>

=>

Subtracting 72.61 to both sides
=>

=> -47.61 = -69 Cos x
=> 47.61 = 69 Cos x
Dividing both sides by 69
=> Cos x = 0.69
Multiplying both sides by

=> x =

=> x = 46.37 degrees