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UKMT Senior Mathematical Challenge, 2025

Geometry Difficulty 3.0 AMC 10/12 Find the answer United Kingdom

Five congruent squares, each of side $2a$ , are placed edge to edge. Two circles with the same centre are drawn through the vertices as shown. What is the area of the region between the two circles?

(A) $2\pi a^2$ (B) $4\pi a^2$ (C) $6\pi a^2$ (D) $8\pi a^2$ (E) $10\pi a^2$

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