Multiple choice

The plan of a survey plotted to a scale of 10 m to 1 cm is reduced in such a way that a line originally 10 cm long now measures 9 cm. the area of the reduced plan is measured as 81 cm2, the actual (m2) of the survey is

  1. 10000

  2. 6561

  3. 1000

  4. 656
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Original scale 1 cm = 10 m. Shrinkage factor = 9/10 = 0.9. Corrected area = Measured area / (SF)^2 = 81 / (0.9)^2 = 81 / 0.81 = 100 cm^2. Since 1 cm = 10 m, 1 cm^2 = 100 m^2. Total area = 100 * 100 = 10,000 m^2.

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