1. **State the problem:** We have a right triangle with sides 21, 20, and 29, where 29 is the hypotenuse. We need to find the ratio equivalent to $\sin(B)$. 2. **Recall the definition of sine:** For an angle in a right triangle, $\sin(\theta) = \frac{\text{opposite side}}{\text{hypotenuse}}$. 3. **Identify the sides relative to angle B:** - Opposite side to angle B is 21. - Adjacent side to angle B is 20. - Hypotenuse is 29. 4. **Write the sine ratio for angle B:** $$\sin(B) = \frac{21}{29}$$ 5. **Check the options:** - $\frac{21}{29}$ - $\frac{21}{20}$ - $\frac{20}{29}$ - $\frac{20}{21}$ 6. **Conclusion:** The correct ratio for $\sin(B)$ is $\frac{21}{29}$.