1. **State the problem:** We need to find the area of the seating region, which is the ring-shaped sector between two concentric circles with radii 117 m and 23 m, both having a central angle of 75°.
2. **Formula for the area of a sector:** The area $A$ of a sector with radius $r$ and central angle $\theta$ (in degrees) is given by
$$A = \frac{\theta}{360} \times \pi r^2$$
3. **Calculate the area of the larger sector (outer radius 117 m):**
$$A_{outer} = \frac{75}{360} \times \pi \times 117^2$$
4. **Calculate the area of the smaller sector (inner radius 23 m):**
$$A_{inner} = \frac{75}{360} \times \pi \times 23^2$$
5. **Find the area of the seating region by subtracting inner area from outer area:**
$$A_{seating} = A_{outer} - A_{inner} = \frac{75}{360} \times \pi (117^2 - 23^2)$$
6. **Simplify inside the parentheses:**
$$117^2 = 13689, \quad 23^2 = 529$$
$$13689 - 529 = 13160$$
7. **Substitute back:**
$$A_{seating} = \frac{75}{360} \times \pi \times 13160$$
8. **Simplify the fraction:**
$$\frac{75}{360} = \frac{\cancel{75}}{\cancel{360}} = \frac{5}{24}$$
9. **Final expression:**
$$A_{seating} = \frac{5}{24} \times \pi \times 13160 = \frac{5 \times 13160}{24} \pi$$
10. **Calculate the numeric value:**
$$\frac{5 \times 13160}{24} = \frac{65800}{24} \approx 2741.6667$$
11. **Multiply by $\pi$ and round to nearest tenth:**
$$A_{seating} \approx 2741.6667 \times 3.1416 = 8607.5 \text{ m}^2$$
**Answer:** The area of the seating region is approximately **8607.5 m²**.
Sector Area 3136D2
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