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The balancing block

A rectangle inside a square. One of its sides is tangent to the quarter circle. What fraction is green as x approaches 0?

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Intermediate

Boxcars

Two regular hexagons share two vertices. What fraction of the area is purple?

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Intermediate

The traffic light

Two congruent circles and a triangle are contained in a circle. What fraction is coloured?

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Beginner

The sailing boat

Three congruent right triangles. What fraction is shaded?

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Intermediate

The corner stone

Four squares inside another square. What fraction is yellow?

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Intermediate

The navel orange

Two quarter circles and a semicircle inside a circle. What fraction of the circle is shaded by the semicircle?

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Advanced

The Bermuda Triangle

A triangle with an inscribed rectangle. What is the maximum red fraction?

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Beginner

Ray of light

A triangle with an inscribed triangle with a parallel side. What fraction is yellow?

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Intermediate

Pandora’s box

A square containing five other squares. What fraction is coloured?

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Advanced

The Common Snowdrop

A square contains a smaller square. Their vertices are cyclically connected as shown, forming four triangles. What is the minimal green area fraction?