For this question, we're going to use the law of cosines.
The law of cosines is the following equation:
[tex]a^2=b^2+c^2-2(b)(c) \cos(A)[/tex]
We know the values of a, b, and c. We want to find the measure of angle A.
[tex]a=4[/tex]
[tex]b=6[/tex]
[tex]c=3[/tex]
Now, plug in these values into the equation.
[tex]4^2=6^2+3^2-2(3)(6) \cos(A)[/tex]
[tex]16=45-36 \cos(A)[/tex]
Add both sides by [tex]36 \cos(A)[/tex] and subtract both sides by 16
[tex]36 \cos(A)=29[/tex]
Divide both sides by 36
[tex]\cos(A)= \dfrac{29}{36}[/tex]
Take the inverse cosine, or arc cosine, of both sides.
Using a calculator, you'll get the following result.
[tex]A \approx 36.3^O[/tex]
The measure of angle A should be 36.3 degrees. Hope this helps! :)
