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UKMT Grey Kangaroo, 2015

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

One corner of a square is folded to its centre to form an irregular pentagon as shown in the diagram. The area of the square is $1$ unit greater than the area of the pentagon. What is the area of the square?

(A) $2$ (B) $4$ (C) $8$ (D) $16$ (E) $32$

Figure for this problem

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