1. The problem involves constructing scale drawings based on a square with side length 6 units on a grid and a scale reference of 18 meters. 2. Each side of the square measures 6 units on the grid. 3. The scale reference indicates that 18 meters corresponds to a certain length on the grid. Since the note says "every 3 units (grid spaces)", we interpret that 3 units on the grid represent a certain real-world length. 4. To find the scale factor, we divide the real-world length by the grid units. Given 18 meters corresponds to 6 units (since 6 units is the side length of the square), the scale factor is: $$\text{Scale factor} = \frac{18}{6} = 3 \text{ meters per unit}$$ 5. Therefore, each unit on the grid corresponds to 3 meters in the real world. 6. The square with side length 6 units corresponds to a real-world square with side length: $$6 \times 3 = 18 \text{ meters}$$ 7. This confirms the scale drawing accurately represents a square of 18 meters per side. Final answer: The scale factor is 3 meters per unit, and the square represents an 18 meter by 18 meter square in real life.