Hello,

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I not 100% sure but I chose C.
Hope this helps.. but good luck :)
I am not quite sure what the question asks for,
But this is what i assume it wants:
Cos A= 0.6489
In this given one, we basically find the size of the angle A
we do cosine inverse on both sides to get the size of the angle A

: It looks like this in the calculator

× cos A=

(0.6489)
(

and cos cancels out)
A=

(0.6489)
A=49.54°
check:
cos 49.54=0.6489 (its right!)
Answer:
Associative property: The addition or multiplication of a several numbers is the same regardless of how the numbers are grouped. The associative property will always involve 3 or more numbers. The parenthesis groups the terms that are considered one unit.