Question: Solve for $c$.
$b = 15$
$20^\circ$
$125^\circ$
$C = [?]$
Law of Sines: $\frac{\sin A}{a} = \frac{\sin B}{b} = \frac{\sin C}{c}$
Round your answer to the nearest hundredth.
Graph/shape: triangle CBA with C at bottom-left, B at bottom-center, and A at upper-right; side CA is labeled $b = 15$, side BA is labeled $c$, angle at C is $20^\circ$, and angle at B is $125^\circ$; position_hint = center
1. **State the problem:** We need to find the length $c$ in triangle CBA where $b = 15$, angle $C = 20^\circ$, and angle $B = 125^\circ$.
2. **Find angle $A$:** The sum of angles in a triangle is $180^\circ$.
$$A = 180^\circ - B - C = 180^\circ - 125^\circ - 20^\circ = 35^\circ$$
3. **Recall the Law of Sines:**
$$\frac{\sin A}{a} = \frac{\sin B}{b} = \frac{\sin C}{c}$$
Here, side $b$ is opposite angle $B$, side $c$ is opposite angle $C$, and side $a$ is opposite angle $A$.
4. **Set up the ratio to find $c$:**
$$\frac{\sin B}{b} = \frac{\sin C}{c} \implies c = b \times \frac{\sin C}{\sin B}$$
5. **Substitute known values:**
$$c = 15 \times \frac{\sin 20^\circ}{\sin 125^\circ}$$
6. **Calculate sine values:**
$$\sin 20^\circ \approx 0.3420$$
$$\sin 125^\circ \approx 0.8192$$
7. **Calculate $c$:**
$$c = 15 \times \frac{0.3420}{0.8192} = 15 \times 0.4175 = 6.2625$$
8. **Round to nearest hundredth:**
$$c \approx 6.26$$
**Final answer:** $c = 6.26$