The area of the forest plot on the base map was measured to be [[$ 2.9 $]] cm [[$ ^ 2 $]], where the measurement error is at most [[$ 0.1 $]] cm [[$ ^ 2 $]]. Calculate the size of the plot in hectares and its maximum error when the base map scale is [[$ 1: $ 20,000]]. (Source: Finnish matriculation exam, spring 2004)

Take a picture of your solution and return it to the submission folder.

Answer: The size of the plot in nature is ha and the maximum error is ha.