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## Twin peaks

A rectangle with three line segments. What is the proportion yellow : red?

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## The ocean sunset

A semicircle is inscribed in a rectangle. What is the minimal covered fraction?

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## The wall

Two congruent rectangles and squares. Proof that the four points are on one circle.

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## The colour purple

A rectangle is split by two perpendicular lines. The four circles pass through vertices and intersection points. Their centres form a purple quadrilateral. What fraction of the large rectangle area does it cover?

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## Between the bars

Two parallel lines support two rectangles. Prove they have equal area.

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## The stained glass

Two congruent rectangles are placed side by side. Two line segments form two coloured quadrilaterals and three triangles. What is the proportion purple : green?

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## The crazy diamond

Three rectangles and four triangles. Given that the red triangles have equal area, prove that the blue rectangles are similar.

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## The rolling mill

A rectangle with a semicircle, a quarter circle and a common tangent. What fraction is blue?

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