1. **State the problem:** We need to find the area of a shape composed of a right-angled triangle ABC (right angle at B) and a semicircle with diameter BC.
2. **Given:**
- AB = 7.6 cm
- AC = 9.5 cm
- Triangle ABC is right-angled at B
3. **Find BC using Pythagoras' theorem:**
$$BC = \sqrt{AC^2 - AB^2} = \sqrt{9.5^2 - 7.6^2}$$
4. Calculate:
$$BC = \sqrt{90.25 - 57.76} = \sqrt{32.49} = 5.7 \text{ cm (to 3 significant figures)}$$
5. **Area of triangle ABC:**
Since the right angle is at B, AB and BC are perpendicular sides.
$$\text{Area}_{\triangle} = \frac{1}{2} \times AB \times BC = \frac{1}{2} \times 7.6 \times 5.7$$
6. Calculate:
$$\text{Area}_{\triangle} = \frac{1}{2} \times 7.6 \times 5.7 = 21.66 \text{ cm}^2$$
7. **Area of the semicircle:**
Radius $r = \frac{BC}{2} = \frac{5.7}{2} = 2.85$ cm
Area of full circle:
$$\pi r^2 = \pi \times 2.85^2 = \pi \times 8.1225$$
Area of semicircle:
$$\frac{1}{2} \pi r^2 = \frac{1}{2} \times \pi \times 8.1225 = 4.06125\pi$$
8. Calculate numerical value:
$$4.06125 \times 3.1416 = 12.76 \text{ cm}^2$$
9. **Total area of the shape:**
$$\text{Area}_{total} = \text{Area}_{\triangle} + \text{Area}_{semicircle} = 21.66 + 12.76 = 34.42 \text{ cm}^2$$
10. **Final answer rounded to 3 significant figures:**
$$34.4 \text{ cm}^2$$
Triangle Semicircle Area 046F4A
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