Sin Alpha
1. **Problem statement:** Find $\sin(\alpha)$ in the given right triangle where $\alpha$ is the angle at vertex A.
2. **Recall the definition of sine in a right triangle:**
$$\sin(\alpha) = \frac{\text{opposite side to } \alpha}{\text{hypotenuse}}$$
3. **Identify the sides relative to angle $\alpha$:**
- Opposite side to $\alpha$ is the side opposite vertex A, which is labeled 12.
- Hypotenuse is the side opposite the right angle at C, labeled 37.
4. **Calculate $\sin(\alpha)$:**
$$\sin(\alpha) = \frac{12}{37}$$
5. **Conclusion:** The correct answer is option C: $\frac{12}{37}$.