Answer:
68.46
Step-by-step explanation:
In order to find the angle, we can use the cosine rule:
c²=a²+b²-2abCos(c)
And rearrange for Cos(c)
(please note that c in this case is x)
So,
x=Cos^(-1) (a²+b²-c²)/2ab
By substituting the values, we get x=Cos^(-1)(4²+4²-4.5^2)/2(4)(4)
=68.46
