Question 1160876
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The area of a circle is found by squaring the radius and multiplying by *[tex \Large \pi].  (*[tex \Large \pi], by the way, should be rendered in plain text as "pi" because "pie" is a pastry item with either a fruit or other sweet filling served as a dessert, or a savory filling served as either a main or side dish.)


You were given the diameter, 14 cm, so you need to first compute the radius which is precisely one-half of the diameter, namely 7 cm.


So, 7 cm squared is 49 multiplied by the required approximation for *[tex \Large \pi], 3.14, results in 153.86 square centimeters.  And this is the answer required by the question.


However, for the question as stated, this answer is absolutely and demonstrably wrong.  Here is why:  ALL measurements are approximations.  You were given 14 cm as a measure of the diameter. But since you were given the approximate measurement to the nearest whole centimeter, you are only guaranteed that the true measurement is in the interval *[tex \Large 13.5\ \leq\ D\ <\ 14.5] based on the rules for rounding. Therefore the true measure of the area, based on the given approximation of *[tex \Large \pi] is in the range


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ 3.14\(\frac{13.5}{2}\)^2 \leq\ A\ <\ 3.14\(\frac{14.5}{2}\)^2]


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ 143.1\ \leq\ A\ <\ 165.0\ \ ] square centimeters


Which renders the decimal fraction on the requested answer utterly meaningless.  If your instructor had wanted an answer correct to two decimal places s/he should have expressed the original diameter measurement as 14.00 centimeters.


Rule:  Never express the FINAL result of a calculation involving measurements to greater precision than the least precise given measurement.
								
								
John
*[tex \LARGE e^{i\pi}\ +\ 1\ =\ 0]
My calculator said it, I believe it, that settles it
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*[tex \Large \ \
*[tex \LARGE \ \ \ \ \ \ \ \ \ \  
								
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