The scale of the drawing is given as the ratio of the actual area to the area on the drawing sheet.
Step 1: The actual area of the roof is \( 6000 \, \text{m}^2 \), and the area on the drawing sheet is \( 240 \, \text{cm}^2 \).
Step 2: Convert the actual area into square centimeters:
\[
6000 \, \text{m}^2 = 6000 \times 10^4 = 60,000,000 \, \text{cm}^2
\]
Step 3: The scale is the ratio of the actual area to the area on the drawing sheet:
\[
\text{Scale} = \frac{\text{Actual area}}{\text{Area on drawing}} = \frac{60,000,000 \, \text{cm}^2}{240 \, \text{cm}^2} = 250,000
\]
To get the scale in terms of 1:n, we take the square root of the ratio:
\[
\sqrt{250,000} = 500
\]
Conclusion: The scale used in the drawing sheet is 1:500.