1. **State the problem:** We are given a triangle with angles $35^\circ$, $105^\circ$, and the side opposite the $105^\circ$ angle is 7 units long. We need to find the length of side $c$ opposite the $35^\circ$ angle using the Law of Sines.
2. **Recall the Law of Sines formula:**
$$\frac{a}{\sin A} = \frac{b}{\sin B} = \frac{c}{\sin C}$$
where $a$, $b$, and $c$ are sides opposite angles $A$, $B$, and $C$ respectively.
3. **Identify known values:**
- Angle $B = 35^\circ$
- Angle $C = 105^\circ$
- Side opposite angle $C$ (side $AB$) = 7
- Side $c$ is opposite angle $B$ (35°)
4. **Find the missing angle $A$:**
$$A = 180^\circ - B - C = 180^\circ - 35^\circ - 105^\circ = 40^\circ$$
5. **Apply Law of Sines to find $c$:**
$$\frac{c}{\sin 35^\circ} = \frac{7}{\sin 105^\circ}$$
6. **Solve for $c$:**
$$c = \frac{7 \times \sin 35^\circ}{\sin 105^\circ}$$
7. **Calculate the sine values:**
$$\sin 35^\circ \approx 0.574\quad \text{and} \quad \sin 105^\circ \approx 0.966$$
8. **Substitute and compute:**
$$c = \frac{7 \times 0.574}{0.966} = \frac{4.018}{0.966} \approx 4.16$$
**Final answer:**
$$c \approx 4.16$$ units
Law Of Sines E2A7Cc
Step-by-step solutions with LaTeX - clean, fast, and student-friendly.