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2013 AMC 12B Question 16

AMC12 · 2013 AMC 12B

Question 16

Let $ABCDE$ be an equiangular convex pentagon of perimeter $1.$ The pairwise intersections of the lines that extend the sides of the pentagon determine a five-pointed star polygon. Let $s$ be the perimeter of this star. What is the difference between the maximum and the minimum possible values of $s?$
  1. $0$
  2. $\dfrac{1}{2}$
  3. $\dfrac{\sqrt5 - 1}{2}$
  4. $\dfrac{\sqrt5 + 1}{2}$
  5. $\sqrt5$