To find the angle \( \theta \) in a right triangle using the inverse of cosine, you would typically use the formula:
\[ \theta = \cos^{-1}\left(\frac{\text{adjacent side}}{\text{hypotenuse}}\right) \]
However, since I don't have access to the specific image or the values of the sides, I can't calculate the angle directly.
If you have the lengths of the sides or values for the adjacent and hypotenuse, you can plug them into the equation above to find \( \theta \). Based on the options provided (59.5°, 90°, 43°, 30.5°), the answer would be one of those angles depending on the calculations you perform.
For example, if the calculation gives you a value close to 59.5° after using the inverse cosine function, then that would be the angle \( \theta \). Please provide the side lengths for a more accurate calculation.