1. **Problem (a):** Find the volume of a solid cylinder with height and diameter both 9 cm.
2. **Formula:** The volume of a cylinder is given by $$V = \pi r^2 h$$ where $r$ is the radius and $h$ is the height.
3. **Step 1:** Calculate the radius. Since diameter $d = 9$ cm, radius $r = \frac{d}{2} = \frac{9}{2} = 4.5$ cm.
4. **Step 2:** Substitute values into the volume formula:
$$V = \pi \times (4.5)^2 \times 9$$
5. **Step 3:** Calculate the square of the radius:
$$4.5^2 = 20.25$$
6. **Step 4:** Multiply:
$$V = \pi \times 20.25 \times 9 = \pi \times 182.25$$
7. **Answer (a):** The volume of the cylinder is $$182.25\pi \text{ cm}^3$$.
8. **Problem (b)(i):** Find the area of a square lawn with perimeter 96 m.
9. **Formula:** The perimeter of a square is $$P = 4s$$ where $s$ is the side length.
10. **Step 1:** Find the side length:
$$s = \frac{P}{4} = \frac{96}{4} = 24 \text{ m}$$
11. **Step 2:** Calculate the area of the square:
$$A = s^2 = 24^2 = 576 \text{ m}^2$$
12. **Answer (b)(i):** The area of the lawn is $$576 \text{ m}^2$$.
13. **Problem (b)(ii):** Calculate the curved surface area of a cylindrical roller with width 1 m and diameter 75 cm.
14. **Note:** Width corresponds to height $h = 1$ m. Diameter $d = 75$ cm = 0.75 m.
15. **Formula:** Curved surface area of a cylinder is $$A = 2 \pi r h$$.
16. **Step 1:** Calculate radius:
$$r = \frac{d}{2} = \frac{0.75}{2} = 0.375 \text{ m}$$
17. **Step 2:** Substitute values:
$$A = 2 \pi \times 0.375 \times 1 = 0.75\pi$$
18. **Step 3:** Calculate numerical value:
$$A \approx 0.75 \times 3.1416 = 2.3562 \text{ m}^2$$
19. **Step 4:** Round to one decimal place:
$$A \approx 2.4 \text{ m}^2$$
20. **Answer (b)(ii):** The curved surface area is approximately $$2.4 \text{ m}^2$$.
Cylinder Volume Area B6405A
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