1. **State the problem:** We need to find the length $x$ of the side opposite the $55^\circ$ angle in a triangle where the other two sides are $19$ m and $17$ m.
2. **Formula used:** The Law of Cosines states:
$$a^2 = b^2 + c^2 - 2bc \cos A$$
where $a$ is the side opposite angle $A$, and $b$ and $c$ are the other two sides.
3. **Assign values:** Here, $a = x$, $b = 19$, $c = 17$, and $A = 55^\circ$.
4. **Apply the formula:**
$$x^2 = 19^2 + 17^2 - 2 \times 19 \times 17 \times \cos 55^\circ$$
5. **Calculate squares:**
$$x^2 = 361 + 289 - 2 \times 19 \times 17 \times \cos 55^\circ$$
6. **Calculate product:**
$$2 \times 19 \times 17 = 646$$
7. **Substitute:**
$$x^2 = 361 + 289 - 646 \times \cos 55^\circ$$
8. **Calculate cosine:**
$$\cos 55^\circ \approx 0.5736$$
9. **Multiply:**
$$646 \times 0.5736 \approx 370.8$$
10. **Simplify:**
$$x^2 = 361 + 289 - 370.8 = 650 - 370.8 = 279.2$$
11. **Take square root:**
$$x = \sqrt{279.2} \approx 16.7$$
**Final answer:**
$$x \approx 16.7 \text{ meters}$$
Law Cosines C718Ab
Step-by-step solutions with LaTeX - clean, fast, and student-friendly.