To find the angle θ in a right triangle where you have the adjacent side (9) and the hypotenuse (12), you can use the cosine function:
\[ \cos(\theta) = \frac{\text{adjacent}}{\text{hypotenuse}} = \frac{9}{12} \]
First, simplify the fraction:
\[ \frac{9}{12} = 0.75 \]
Now, to find θ, use the inverse cosine (arccos):
\[ \theta = \cos^{-1}(0.75) \]
Using a calculator:
\[ \theta \approx 41.4^\circ \]
So, rounding to the nearest tenth:
\[ \theta \approx 41.4^\circ \]
Thus, the final answer is:
\(\theta \approx 41.4°\)