is E the OA?
The radius of medallion - the area of the center part = area of the border
pi r^2- pi(r-s)^2
pi (r^2 - r^2 + 2rs - s^2 )
= pi (2rs - s^2 )
please let me know if it help you
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Source: Beat The GMAT — Problem Solving |
moliver's answer is correct.
Just wanted to point out that whenever we have a shaded region, we have:
area of whole figure = area of shaded region + area of non-shaded region
they'll almost always ask you to compute the area of the shaded region, so:
area of shaded region = area of whole figure - area of non-shaded region
In this question, the radius of the whole figure (the medallion) is "r" while the radius of the non-shaded region is "r - s"
Just wanted to point out that whenever we have a shaded region, we have:
area of whole figure = area of shaded region + area of non-shaded region
they'll almost always ask you to compute the area of the shaded region, so:
area of shaded region = area of whole figure - area of non-shaded region
In this question, the radius of the whole figure (the medallion) is "r" while the radius of the non-shaded region is "r - s"
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