1. **State the problem:** Calculate the area of the shaded region inside a rectangle of length 12 m and height 7 m, with two semicircles on the left and right sides inside the rectangle, each with radius 3.5 m (half the height).
2. **Identify the shapes and formulas:**
- Area of rectangle: $A_{rect} = \text{length} \times \text{height} = 12 \times 7$
- Area of a semicircle: $A_{semi} = \frac{1}{2} \pi r^2$
- The shaded area is the rectangle area minus the areas of the two semicircles (since the semicircles curve inward, the shaded region excludes them).
3. **Calculate the rectangle area:**
$$A_{rect} = 12 \times 7 = 84$$
4. **Calculate the radius of each semicircle:**
$$r = \frac{7}{2} = 3.5$$
5. **Calculate the area of one semicircle:**
$$A_{semi} = \frac{1}{2} \pi (3.5)^2 = \frac{1}{2} \pi \times 12.25 = 6.125\pi$$
6. **Calculate the total area of two semicircles:**
$$2 \times 6.125\pi = 12.25\pi$$
7. **Calculate the shaded area:**
$$A_{shaded} = A_{rect} - 12.25\pi = 84 - 12.25\pi$$
8. **Approximate the shaded area using $\pi \approx 3.1416$:**
$$12.25 \times 3.1416 = 38.48$$
$$A_{shaded} \approx 84 - 38.48 = 45.52$$
**Final answer:** The area of the shaded region is approximately $45.52$ square meters.
Shaded Area F2B0B3
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