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Beginner

The star gazer

A square divided by a diagonal and another line segment. What fraction of its area is purple?

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Beginner

The chess board

A square is divided by six line segments. What fraction is brown?

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Intermediate

The residue

A parabola is tangent to two sides of a square and to the hypotenuse of an isosceles triangle. The three tangency points are shown. What fraction of the square is green?

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Beginner

Down the tree

Two overlapping congruent isosceles triangles. What fraction of the total area is green?

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Intermediate

Lost in rotation

Four equilateral triangles inscribed in a fifth one. What fraction of the latter is coloured?

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Beginner

The dog ear

A square contains a triangle. What fraction of the square is red?

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Beginner

Arc de Triomphe

A parabola passing through a square’s bottom vertices and tangent to its top side. What fraction is blue?

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Beginner

Square eyes

A square with four quarter circles of which the intersection points are the vertices of a yellow quadrilateral. What fraction of the total area is yellow?

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Advanced

The Queen’s chamber

A right triangle with three squares forming a smaller inner triangle. What is the maximal blue fraction?

Categories
Beginner

The life net

The vertices of a regular hexagon are connected to midpoints of opposing sides. What fraction is red?