Problem

2009 AMC 12A Problem 19

Andrea inscribed a circle inside a regular pentagon, circumscribed a circle around the pentagon, and calculated the area of the region between the two circles. Bethany did the same with a regular heptagon (7 sides). The areas of the two regions were A and B, respectively. Each polygon had a side length of 2. Which of the following is true?

\textbf{(A)}\ A = \frac {25}{49}B\qquad \textbf{(B)}\ A = \frac {5}{7}B\qquad \textbf{(C)}\ A = B\qquad \textbf{(D)}\ A = \frac {7}{5}B\qquad \textbf{(E)}\ A = \frac {49}{25}B


Full credit goes to MAA for authoring these problems. These problems were taken on the AOPS website.


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