Question 820990
Simplest idea is to try to compare the two circles:  The ideal one with the errored one.


Ideal 60 m radius:  A=pi*6000^2 in square centimeters.
Too Big radius+0.01 cm:   a=pi*6000.01^2 square centimeters.


Actually, since you are interested in money cost for area in square METERS, you may want this way:


Units of SQUARE METERS:
Ideal:  {{{A=pi*60^2}}}
Too Big:   {{{a=pi*(60+0.0001)^2}}}
Excess Area is then {{{pi(60.0001^2-60^2)}}}
'
Take advantage of Difference Of Squares.
Excess area is {{{highlight_green(pi(60.0001+60)(60.0001-60))}}}
{{{highlight_green(pi*120.0001*0.0001)}}}
and having only two significant figures, an adequate area answer for the excess is {{{highlight(0.12)}}} square meters.





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The cost of this error is 27 dollars.