To find \( \sin \theta \) in a right triangle, we can use the definition of sine in relation to the triangle's sides. Specifically,
\[ \sin \theta = \frac{\text{opposite side}}{\text{hypotenuse}} \]
In this case, \( \theta \) is the angle opposite side \( b \). Here, the opposite side to \( \theta \) is \( b \), and the hypotenuse is \( c \).
Given the values:
- \( c = 17 \) in (hypotenuse)
- \( b = 15 \) in (opposite side to angle \( \theta \))
We can substitute these values into the sine formula:
\[ \sin \theta = \frac{b}{c} = \frac{15}{17} \]
Thus, the value of \( \sin \theta \) is:
\[ \sin \theta = \frac{15}{17} \]