To find the angle θ across from the side labeled 3 in the right triangle using the inverse cosine function, you can use the formula:
\[ \cos(\theta) = \frac{\text{adjacent}}{\text{hypotenuse}} \]
In this triangle, the adjacent side (the one next to angle θ) is 4, and the hypotenuse is 5. So we have:
\[ \cos(\theta) = \frac{4}{5} \]
Now, take the inverse cosine to find angle θ:
\[ \theta = \cos^{-1}\left(\frac{4}{5}\right) \]
Calculating this:
\[ \theta \approx 36.87° \]
Rounding to the nearest whole degree gives us:
\[ \theta \approx 37° \]
So the correct answer is:
37°