Given:
There are given that the triangle ABC.
Where,

Step-by-step explanation:
To find the value of angles, we need to use the cosine rule:
So,
From the cosine rule:

Now,
First, find the angle for A,
So,
From the formula to find the angle A:

Then,
Put the value of a, b, and c into the above formula:
So,

Then,
Subtract 1940 from both side of the equation:

Then,
Divide by -1904 in both side of the above equation:
So,

Now,
From the formula to find the angle for B:

Then,
Subtract 2009 from both sides of the equation:
So,

Now,
To find the angle C, we need to use the interior angle concept:
From the interior angle concept, addition of interior angle of any triangle is equal to 180 degrees.
Then,

Then,
Put the value of angle A and angle B into the above formula:
So,
![\begin{gathered} \angle A+\angle B+\angle C=180^(\degree) \\ 67.9^(\degree)+64.2^(\degree)+\angle C=180^(\degree) \\ 132.1^(\degree)+\operatorname{\angle}C=180^{\operatorname{\degree}} \\ \operatorname{\angle}C=180^(\degree)-132.1^(\degree) \\ \angle C=47.9 \end{gathered}]()
Final answer:
Hence, the value of angles A, B, and C are shown below:
