1. **State the problem:** Calculate the area of one fence slat composed of a rectangle and a semi-circle on top. 2. **Given:** - Width of rectangle = 20 cm - Height of rectangle = 200 cm (2 meters converted to cm) - Diameter of semi-circle = 20 cm, so radius $r = \frac{20}{2} = 10$ cm - Use $\pi = 3.14$ 3. **Formula for area:** - Area of rectangle = width $\times$ height - Area of semi-circle = $\frac{1}{2} \pi r^2$ 4. **Calculate each area:** - Rectangle area = $20 \times 200 = 4000$ cm$^2$ - Semi-circle area = $\frac{1}{2} \times 3.14 \times 10^2 = \frac{1}{2} \times 3.14 \times 100 = 157$ cm$^2$ 5. **Total area of one slat:** $$\text{Area} = 4000 + 157 = 4157 \text{ cm}^2$$ 6. **Answer:** The area of one slat is $4157$ cm$^2$.