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UKMT Junior Kangaroo, 2017

Geometry Difficulty 2.0 Junior Find the answer United Kingdom

Three congruent isosceles trapeziums are assembled to form an equilateral triangle with a hole in the middle, as shown in the diagram. What is the perimeter of the hole?

(A) $3a + 6b$ (B) $3b - 6a$ (C) $6b - 3a$ (D) $6a + 3b$ (E) $6a - 3b$

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