1. **Problem statement:**
Find the area of the shaded region in a large circle with center $Q$ and area $9\pi$ square inches, where three equal semicircles are drawn on the diameter of the large circle.
2. **Given data:**
- Area of the large circle $Q$ is $9\pi$.
- Three equal semicircles are drawn on the diameter of the large circle.
3. **Find the radius of the large circle:**
The area of a circle is given by the formula:
$$\text{Area} = \pi r^2$$
Given:
$$9\pi = \pi r^2$$
Divide both sides by $\pi$:
$$\cancel{\pi}9 = \cancel{\pi} r^2 \implies 9 = r^2$$
Taking the square root:
$$r = 3$$
4. **Diameter of the large circle:**
$$\text{Diameter} = 2r = 2 \times 3 = 6$$
5. **Radius of each small semicircle:**
Since three equal semicircles are drawn on the diameter, each semicircle has diameter:
$$\frac{6}{3} = 2$$
So radius of each semicircle is:
$$r_{small} = \frac{2}{2} = 1$$
6. **Area of one small semicircle:**
Area of a semicircle is half the area of a full circle:
$$A_{semicircle} = \frac{1}{2} \pi r^2 = \frac{1}{2} \pi (1)^2 = \frac{\pi}{2}$$
7. **Total area of three small semicircles:**
$$3 \times \frac{\pi}{2} = \frac{3\pi}{2}$$
8. **Area of the shaded region:**
The shaded region is the area of the large circle minus the area covered by the three small semicircles:
$$9\pi - \frac{3\pi}{2} = \frac{18\pi}{2} - \frac{3\pi}{2} = \frac{15\pi}{2}$$
**Final answer:**
$$\boxed{\frac{15\pi}{2}}$$ square inches
Semicircle Shaded Area Efcbb0
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