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2021 AMC 10C Question 19

AMC10 · 2021 AMC 10C

Question 19

A disk of radius $1$ rolls all the way around the inside of a square of side length $s > 4$ and sweeps out a region of area $A.$ A second disk of radius $1$ rolls all the way around the outside of the same square and sweeps out a region of area $2A.$ The value of $s$ can be written as $a+\dfrac{b\pi}{c},$ where $a,$ $b,$ and $c$ are positive integers and $b$ and $c$ are relatively prime. What is $a+b+c?$
  1. $10$
  2. $11$
  3. $12$
  4. $13$
  5. $14$