1. Stating the problem: We need to find the volume and surface area of two vertical cylinders. 2. Formula for a cylinder: - Volume: $$V = \pi r^2 h$$ - Surface area: $$A = 2\pi r (r + h)$$ 3. Important rules: - $r$ is the radius of the base. - $h$ is the height of the cylinder. - Use $\pi \approx 3.1416$ for calculations. 4. Problem a: - Given diameter = 20 cm, so radius $r = \frac{20}{2} = 10$ cm. - Height $h = 22$ cm. Calculate volume: $$V = \pi \times 10^2 \times 22 = \pi \times 100 \times 22 = 2200\pi$$ Calculate surface area: $$A = 2\pi \times 10 \times (10 + 22) = 20\pi \times 32 = 640\pi$$ 5. Problem b: - Given diameter = 50 cm, so radius $r = \frac{50}{2} = 25$ cm. - Height $h = 7$ cm. Calculate volume: $$V = \pi \times 25^2 \times 7 = \pi \times 625 \times 7 = 4375\pi$$ Calculate surface area: $$A = 2\pi \times 25 \times (25 + 7) = 50\pi \times 32 = 1600\pi$$ 6. Final answers: - a. Volume = $2200\pi \approx 6911.5$ cm$^3$, Surface area = $640\pi \approx 2010.6$ cm$^2$ - b. Volume = $4375\pi \approx 13744.0$ cm$^3$, Surface area = $1600\pi \approx 5026.5$ cm$^2$