1. **Stating the problem:** We need to find how many liters of paint are required to paint 10,000 wooden blocks. Each block consists of a triangular prism and a square part with given dimensions in decimeters (dm). One liter of paint covers 3 m². 2. **Convert dimensions to meters:** Since 1 dm = 0.1 m, - Triangular base edges: $2.2\,\text{dm} = 0.22\,\text{m}$ - Height of triangular prism: $2\,\text{dm} = 0.2\,\text{m}$ - Square side length: $4\,\text{dm} = 0.4\,\text{m}$ 3. **Calculate the area of the triangular base:** The triangle has base $b=0.22$ m and height $h=0.2$ m. $$\text{Area}_{\triangle} = \frac{1}{2} \times b \times h = \frac{1}{2} \times 0.22 \times 0.2 = 0.022\,\text{m}^2$$ 4. **Calculate the perimeter of the triangular base:** Assuming an equilateral triangle with sides 0.22 m, $$P = 3 \times 0.22 = 0.66\,\text{m}$$ 5. **Calculate the lateral surface area of the triangular prism:** Height of prism is 0.4 m (the square side length), so $$\text{Lateral area} = P \times \text{height} = 0.66 \times 0.4 = 0.264\,\text{m}^2$$ 6. **Calculate the total surface area of the triangular prism:** It has two triangular bases and the lateral area, $$\text{Total prism area} = 2 \times 0.022 + 0.264 = 0.308\,\text{m}^2$$ 7. **Calculate the area of the square face:** $$\text{Area}_{\square} = 0.4 \times 0.4 = 0.16\,\text{m}^2$$ 8. **Calculate total surface area of one block:** $$\text{Total area} = 0.308 + 0.16 = 0.468\,\text{m}^2$$ 9. **Calculate total area for 10,000 blocks:** $$10,000 \times 0.468 = 4680\,\text{m}^2$$ 10. **Calculate liters of paint needed:** Since 1 liter covers 3 m², $$\text{Liters} = \frac{4680}{3} = 1560$$ **Final answer:** You need 1560 liters of paint to cover all 10,000 blocks.