Categories
Intermediate

The crazy quilt

A parallelogram is divided into several areas. What is the area X of the blue trapezium?

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Advanced

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?

Categories
Advanced

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?

Categories
Advanced

The orange belt

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

Categories
Beginner

The skyscraper

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

Categories
Beginner

The first cut

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

Categories
Intermediate

The balance sheet

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

Categories
Beginner

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?

Categories
Intermediate

Velocipede II

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