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## Out of proportion

An equilateral triangle containing a parallelogram, another equilateral triangle and a circular arc that is tangent in its base vertices. What is the proportion pink : blue?

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## Silent circle

A large triangle with one side tangent to a circle. The tangency point is the vertex of a blue parallelogram. What is the red area?

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## The orange belt

Three squares and three shared vertices. Prove that the orange quadrilateral is in fact a parallelogram.

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## The skyscraper

A blue parallelogram with an extended diagonal. What is the proportion green : orange?

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## The first cut

Using one straight cut, divide this triangle in two pieces. Paste them together to form a parallelogram with perimeter 19.

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## The balance sheet

A unit square and a parallelogram. What’s the area of the latter?

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## The parquet floor

A unit rhombus is surrounded by four congruent parallelograms. All five quadrilaterals have equal area. What are the parallelogram sides x and y?

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## Velocipede II

Two circles of area π and 9π respectively are contained in a parallelogram. What’s its area?